Answer: cosiest

AnswerCrossword Clue
COSIESTMost snug
cosiestCOSY, snug and comfortable, also COZY
cosiestAvoiding or not offering challenge or difficulty; complacent
cosiest(of a relationship or conversation) Intimate and relaxed
cosiestGiving a feeling of comfort, warmth, and relaxation
cosiest(of a transaction or arrangement) Working to the mutual advantage of those involved (used to convey a suspicion of corruption)