Why do sexual human parts have the same name as animals?

@damselfly The word "cock" also means a "tap", or "valve"; as in "stop-cock" (your home's water isolating valve), "try-cock" (a water-level test-valve); etc.

I wonder if the fire-arms "cock" was originally a fanciful comparison of its shape on a flint-lock gun, with the fleshy comb on a cockerel's head.

@ArishMell English has never had enough words. No wonder we've nicked words from other languages and resorted to using the same word for many things.

@damselfly Saves having to invent ones needlessly where the meaning is obvious from the context, I suppose.

The key to unlocking the curious alternative uses of a simple word is to examine its likely etymology and historical context.

What I do find far more strange is the fad for taking elegant words and mangling them into ugly, clumsy self-parodies, such as "inspi-ray-shun-ul" for "inspiring".

Or for using metaphorically, technical terms without really understanding them, sometimes changing unwittingly but totally the meaning of the message. The classic example is perhaps "epicentre". Also, so many musicians and art critics who ought know better, continue to use acoustic (adjective) for acoustics (noun), and resonant when they mean reverberant.