Where does the phrase "taking the piss" come from?

TAKE THE PISS
Nothing literal about this one, you will be pleased to hear. It’s usually said that the phrase derives from an older one, piss-proud, which refers to having an erection when waking up (Morning Wood)in the morning, which is usually attributed to a full bladder (proud here being an obvious pun on its senses of something raised or projecting and of something in which one may take satisfaction).

It’s first recorded, as so many such indecorous expressions are, in Francis Grose’s A Classical Dictionary of the Vulgar Tongue; in the second edition of 1788 he wrote: “Piss-proud, having a false erection. That old fellow thought he had an erection, but his — was only piss-proud; said of any old fellow who marries a young wife”.

This developed into a figurative sense of somebody who had an exaggerated idea of his own importance. So to take the piss is to deflate somebody, to disabuse them of their mistaken belief that they are special. It’s not recorded before the beginning of the twentieth century.

In case you were wondering, Morning Wood, or Mahogany stems from the fact that wood is hard and erect.

Urinate, vulgar slang. It is actually a semi-idiom and its origin is like that of all idioms. Evolved. You made me think that is for sure. You are getting my two thumbs up.

In the UK, urine was collected for the tanning industry and shipped from southern cities up the East coast. The collection was paid for locally in cash and the industry was significant if not particularly acceptable. Sea captains arriving in the north would be unwilling to divulge their realy cargo and would state that they were carrying wine. Their deception would be challenged by cry that they were 'taking the piss'.

I would bet from England

According to Partridge's Concise Dictionary of Slang and Unconventional English, Piss is the vulgarism, Urine, originating in Middle English. In the 1920's the term came to mean both a poor quality drink, 'taking the piss,' and heavy drinking, '(go) on the piss'. 'Taking a piss,' re-popularized in the 1960's still means to urinate.