What is the definition of charge?

Basically its the excess or deficiency of electrons in an atom, in other words, it is the quantity of unbalanced electricity in a body.

Electric charge is a basic property in elementary particles of matter. The protons in an atom, for example, have a positive charge, the electrons have a negative charge, and the neutrons have zero charge. In an ordinary atom, the number of protons equals the number of electrons, so the atom normally has no net electric charge. An atom becomes negatively charged if it gains extra electrons, and it becomes positively charged if it loses electrons; atoms with net charge are called ions.

charge (chärj)
v. charged, charg·ing, charg·es
v.tr.
1. To impose a duty, responsibility, or obligation on: charged him with the task of watching the young swimmers.
2. To set or ask (a given amount) as a price: charges ten dollars for a haircut.
3. To hold financially liable; demand payment from: charged her for the balance due.
4. To postpone payment on (a purchase) by recording as a debt: paid cash for the stockings but charged the new coat.
5.
a. To load to capacity; fill: charge a furnace with coal.
b. To saturate; impregnate: The atmosphere was charged with tension.
6. To load (a gun or other firearm) with a quantity of explosive: charged the musket with powder.
7. To instruct or urge authoritatively; command: charged her not to reveal the source of information.
8. Law To instruct (a jury) about the law, its application, and the weighing of evidence.
9. To make a claim of wrongdoing against; accuse or blame: The police charged him with car theft. Critics charged the writer with a lack of originality.
10. To put the blame for; attribute or impute: charged the accident to the driver's inexperience.
11. To attack violently: The troops charged the enemy line.
12. Basketball To bump or run into (a defender) illegally while in possession of the ball or having just made a pass or shot.
13. Sports
a. To bump (an opponent) so as to knock off balance or gain control of the ball, as in soccer.
b. To body-check (an opponent) illegally, from behind or after taking more than two strides, as in ice hockey.
14. Electricity
a. To cause formation of a net electric charge on or in (a conductor, for example).
b. To energize (a storage battery) by passing current through it in the direction opposite to discharge.
15. To excite; rouse: a speaker who knows how to charge up a crowd.
16. To direct or put (a weapon) into position for use; level.
17. Heraldry To place a charge on (an escutcheon).
v.intr.
1. To rush forward in or as if in a violent attack: dogs trained to charge at intruders; children charging through the house.
2. To demand or ask payment: did not charge for the second cup of coffee.
3. To postpone payment for a purchase.
4. Accounting To consider or record as a loss. Often used with off.
n.
1.
a. Expense; cost.
b. The price asked for something: no charge for window-shopping.
2.
a. A weight or burden; a load: a freighter relieved of its charge of cargo.
b. The quantity that a container or apparatus can hold.
3. A quantity of explosive to be set off at one time.
4. An assigned duty or task; a responsibility: The commission's charge was to determine the facts.
5. One that is entrusted to another's care or management: the baby sitter's three young charges.
6.
a. Supervision; management: the scientist who had overall charge of the research project.
b. Care; custody: a child put in my charge.
7. An order, command, or injunction.
8. Law Instruction given by a judge to a jury about the law, its application, and the weighing of evidence.
9. A claim of wrongdoing; an accusation: a charge of murder; pleaded not guilty to the charges.
10.
a. A rushing, forceful attack: repelled the charge of enemy troops; the charge of a herd of elephants.
b. The command to attack: The bugler sounded the charge.
11. A debt or an entry in an account recording a debt: Are you paying cash or is this a charge?
12. A financial burden, such as a tax or lien.
13. Symbol q Physics
a. The intrinsic property of matter responsible for all electric phenomena, in particular for the force of the electromagnetic interaction, occurring in two forms arbitrarily designated negative and positive.
b. A measure of this property.
c. The net measure of this property possessed by a body or contained in a bounded region of space.
14. Informal A feeling of pleasant excitement; a thrill: got a real charge out of the movie.
15. Heraldry Any figure or device represented on the field of an escutcheon.
Idioms:
in charge
1. In a position of leadership or supervision: the security agent in charge at the airport.
2. Chiefly British Under arrest.
in charge of
Having control over or responsibility for: You're in charge of making the salad.

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[Middle English chargen, to load, from Old French chargier, from Late Latin carricre, from Latin carrus, Gallic type of wagon, of Celtic origin; see kers- in Indo-European roots.]
Synonyms: charge, imbue, impregnate, permeate, pervade, saturate, suffuse
These verbs mean to cause to be filled with a particular mood or tone: an atmosphere charged with excitement; poetry imbued with lyricism; a spirit impregnated with lofty ideals; optimism that permeates a group; letters pervaded with gloom; a play saturated with imagination; a heart suffused with love. See Also Synonyms at care.

The American Heritage® Dictionary of the English Language, Fourth Edition copyright ©2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.


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charge
Verb
[charging, charged]
1. to ask (an amount of money) as a price
2. to enter a debit against a person's account for (a purchase)
3. to accuse (someone) formally of a crime in a court of law
4. to make a rush at or sudden attack upon
5. to fill (a glass)
6. to cause (an accumulator or capacitor) to take and store electricity
7. to fill or saturate with liquid or gas: old mine workings charged with foul gas
8. to fill with a feeling or mood: the emotionally charged atmosphere
9. Formal to command or assign: the president has charged his foreign minister with trying to open talks
Noun
1. a price charged for something; cost
2. a formal accusation of a crime in a court of law
3. an onrush or attack
4. custody or guardianship: in the charge of the police
5. a person or thing committed to someone's care: a nanny reported the cruel father of one of her charges to social workers
6.
a. a cartridge or shell
b. the explosive required to fire a gun
7. Physics
a. the attribute of matter responsible for all electrical phenomena, existing in two forms, positive and negative
b. the total amount of electricity stored in a capacitor or an accumulator
8. in charge of in control of and responsible for: in charge of defence and foreign affairs [Old French chargier to load]

you could have googled that urself. (no sarcasm intended)

a charge is stored energy

positive and negative ions that attract each other.