Effete is an adjective describing something as feminine or effeminate. An alternative definition is for something to lack effectiveness, to not have strength or bravery or to be unable to act.
Its derivatives include effetely and effeteness.
Than vs. then
Fish vs. fishes
Adviser vs. advisor
Favorite vs. favourite
Affect vs. effect
Center vs. centre
Canceled vs. cancelled
Realise vs. realize
Practice vs. practise
Learned vs. learnt
Its vs. it’s
Alumna, alumnae, alumni, alumnus
Gray vs. grey