"un" = not
uneventful = not eventful
unaware = not aware
what does a prefex mean
it means good
penta-
The prefix "re-" means again or back. It is commonly used in English to indicate repetition or restoration of an action or state.
Pent - as in pentagon (five-sided shape)
I hope you mean 'What do the initials 'UN' mean - United Nations.
un tabier doesn't mean anything, un tablier means un apron
pro means forward or before
Quad is the prefix. It means four. A quadrilateral has four sides.
It's "un accomplissement" and it does mean an accomplishment or fulfillment
Un fou is a madman.
Un cheval is a horse.