The Idiom Attic - a collection of hundreds of English idioms, each one explained.
The meaning of "man cave"
" Man cave "
A shed or some other retreat that men decorate in the way they choose (with or without their male friends) and use to relax in traditional male pursuits.
After I retired Sheila was getting so fed up with me being around the house that she made me turn the outhouse into a man cave. Now the guys come round each afternoon to play cards and watch tv and I've made a sculpture out of beer cans.