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.
Gray vs. grey
Realise vs. realize
Canceled vs. cancelled
Learned vs. learnt
Than vs. then
Fish vs. fishes
Its vs. it’s
Center vs. centre
Favorite vs. favourite
Alumna, alumnae, alumni, alumnus
Practice vs. practise
Adviser vs. advisor
Affect vs. effect