ἐθελοθρησκεία G1479
ethelothrēskeía · eth-el-oth-race-ki'-ah · Noun Feminine
from θέλω and θρησκεία; voluntary (arbitrary and unwarranted) piety, i.e. sanctimony:--will worship.
1 Occurrence in the King James Bible
Colossians 2:23Which things have indeed a shew of wisdom in will worship, and humility, and neglecting of the body; not in any honour to the satisfying of the flesh.