Idioms, what do they mean?

[Scriveyn]

I have been wondering about "to take the mickey out of someone"

Here's a website (Take our word for it) from people who know their etymology. Sadly it is very rarely updated these days.

It's rhyming slang. The original was to take the piss which means "to deride, to make fun of". Mike (or Mickey) Bliss is rhyming slang for "piss" so, applying the usual rhyming slang rules, we substitute Mickey Bliss for piss then drop the rhyming portion. Hence, to take the Mickey.
http://www.takeourword.com