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