Origin- From Greek mikros, small. Very small. micro-miniskirt In the International System of Units and other metric systems of units, multiplying the unit to which it is attached by 10-6. Symbol: µ (official), mc (unofficial). microgram Note: The symbol mc is used in non-scientific contexts where readers might not understand the official symbol, µ. For example, on bottles of vitamin tablets, micrograms is often abbreviated to mcg. microabscess microaneurysm microatoll microbiology microbacillus microbiota microblade microbody microbubble microcatchment microcapsule microcar microcellular microcellular microchromosome microcirculation microcolony microconidium microcrater microculture microdrop microdroplet microearthquake microeconomics microexplosion microexplosive microfauna microferment microflora microfossil microfungus microgonid microgonidial microgonidium microgram micrograver microhabitat microinvertebrate microlaser microlitre, microliter micrometastasis micrometazoa micrometazoan micrometer (the instrument) micrometre, micrometer (the unit of length) micromodule micronodule micronodular microparasite microparasitic microparticle microphenocryst microphysics micropulsation micropower microquantity microrobot microschizont microskirt microstylar microtektite microvegetation microvesicle microwave microwire microzone