it originally started as a concatenation of (big) muff (π) and wiggler - 2 electro-harmonix effects pedals
muff in English has multiple meanings:
the effects pedal;
a tube made of fur or other warm material into which the hands are placed for warmth;
and
slang for female genitalia/pubic hair
wiggler is more straight forward someone who wiggles
I don't see electro-harmonix changing the name of their effect pedal after 50 years or so...
it's just a bit of schoolboy humour - that really hurts no one and has no intention of offence - but remember in English you cannot give offence, you can only take it... some people are extremely over sensitive and those that are tend to shout the loudest!
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities