-D-

Daft, Thick:
    Stupid, Moron

Dinner Jacket:
    Tuxedo

Diversion:
   Detour

DIY, Decorate:
    Home Improvement, Re-Model
("We need to re-model the bathroom next year dear")

Doctor's Surgery:
   Doctor's Office
(After all, it's their office isn't it? They don't perform surgery there!)

Draughts:
   Checkers

Drawing Pin:
    Tack

Dressing Gown:
    Robe

Dual-Carriageway:
   Divided Highway

Dummy:
    Pacifier

Dustbin:
    Garbage, Trash can

Dustcart:
    Garbage Truck

Dustman:
    Garbage man

Duvet:
   Comforter

-E-

Earth (electrical):
    Ground

Engaged (phone):
   Busy

En-Suite:
    No equivalent

Estate (inner city):
    'The Projects'

Estate (area of new houses):
    Sub-Division

Estate (car):
    Station Wagon

Estate-Agent:
    Real-Estate Agent

Ex-Directory:
    Unlisted

-F-

Fag:
   Cigarette
(Call it a 'fag' in the States and you'll wish you hadn't.
Well..I suppose if you're in the right area...).

Fag End:
   Cigarette Butt
(I would advise you never to say 'fag end' in the States!)

Fairy Cake:
    Cupcake

Fairy Lights:
   Christmas Lights
(Don't say 'fairy' in the States unless you want to be looked at in a different light!)

Fancy:
    Like

Fancy Dress (Party):
    Costume Party

Fanny:
   hmmm, You Brit's use the word 'fanny' to mean a woman's front-side, while American's use it to mean their Butt, Bum (mainly by middle-age women).

Father Christmas, Santa Claus:
    Santa Claus (never Father Christmas)

Fire Brigade:
    Fire Department

First, Second, Third, Fourth year (at university & high school):
    Freshman, Sophmore, Junior, Senior

Fishfingers:
    Fishsticks

Flannel:
    Washcloth

Flask:
    Thermos, Thermos Bottle

Flat:
   Apartment

Flyover:
   Overpass

Football:
    Soccer

Football Boots:
   Cleats

Footpath:
    Hiking Trail, Trail

Fortnight:
    not used

Freephone:
    Toll-Free
("Just call our toll-free number and one of our salesmen will get back to you")

Fringe:
   Bangs

Full Stop:
    Period