Merriam-Webster's Collegiate Dictionary:
affaire
affect
affectability
affectable
affectation
affected
affectedly
affectedness
affecting
affectingly
affection
affectional
affectionally
affectionate
affectionately
affectioned
affectionless
affective
affective disorder
affectively
affectivity
affectless
affectlessness
affenpinscher
afferent
afferently
affiance
affiant
afficionado
affidavit
affiliate
affiliated
affiliation
affine
affined
affinely
affinity
affinity card
affinity chromatography
affinity group
affirm
affirmable
affirmance
affirmation
affirmative
affirmative action
affirmatively
affix
affixable
affixal
affixation
affixial
affixment
afflatus
afflict
affliction
afflictive
afflictively
affluence
affluency
affluent
affluently
afford
affordability
affordable
affordably
afforest
afforestation
affray
affricate
affricative
affright
affront
afft
affusion
afghan
afghan hound
afghani
afghanistan
aficionada
aficionado
afield
afire
afl
afl-cio
aflame
aflatoxin
afloat
aflutter
afognak
afonso
afoot
afore
aforementioned
aforesaid
aforethought
afoul of
