I came across a very long list of French words that are used regularly in English and have edited it down. It's amazing how many words we use from other languages and don't even register the fact. So, for all of those stupid English people that don't like the French... here are just a selection of phrases that you may want to avoid from now on as they are all French.
aide-mémoire "memory aid"
à la carte "on the menu"
art déco "decorative art" - Short for art décoratif.
art nouveau "new art"
au fait "conversant, informed"
bon appétit "good appetite" - The closest English equivalent is "Enjoy your meal."
carte blanche "blank card" - Free hand, ability to do whatever you want/need.
chic "stylish" - Chic sounds more chic than "stylish.
cul-de-sac "bottom (butt) of the bag" - An English dead-end street.
double entendre "double hearing" - A 'Carry On' moment.
en route "on route" - On the way.
fait accompli "done deed"
faux pas "false step, trip" - foolish mistake.
gauche "left, awkward"
ménage à trois "household of three" - Sexual threesome.
objet d'art "art object"
raison d'être "reason for being"
soirée "evening" - An elegant party.
soupçon "suspicion" - A small amount of something.
souvenir "memory, keepsake"
tête-à-tête "head to head"
tour de force "turn of strength" - Something which takes a great deal of skill to accomplish.
vol-au-vent "flight of the wind" - Light pastry shell filled with meat or fish with sauce.