Answer: vain

AnswerCrossword Clue
VAINIneffectual
VAIN"You're So ..." (Simon song)
VAIN"You're So ..." (Carly Simon hit)
VAINIn love with oneself
VAINSelf-centered
VAINStuck on oneself
VAIN"You're So ..." (Carly Simon song)
VAINNarcissistic
VAINPeacocklike
VAINEgoistic
VAINBigheaded
VAINIrreverently, after "in"
VAINPuffed-up
VAINSelf-inflating?
VAINIn .. (without effect)
VAINHaving a swelled head
VAINOverproud
VAINUnsuccessful
VAINSelf-complacent
VAINFutile.
vainconceited
VAINPuffed up
VAINEgotistical
VAINConceited
VAINNose-in-the-air
VAINFond of oneself
VAINUseless
VAINFull of oneself
VAINStuck-up
VAINFar from modest
VAINGlued to the mirror, maybe
VAINLike Narcissus
VAINSelf-involved
VAINOverweening
VAINFutile
VAINFruitless
VAINSelf-absorbed
VAINHubristic
VAIN"You're So ..": Carly Simon hit
VAINUnable to merely walk past a mirror, say