fiacca
Fiacca is an Italian adjective used to describe something or someone as languid, weak, or lacking energy. It conveys a sense of dullness, fatigue, or low vitality and can apply to a person, a day, a performance, or an atmosphere. The nuance is that of insufficient vigor rather than brief tiredness.
In terms of grammar, fiacco is the masculine form and fiacca the feminine; the adjective commonly appears
Origins and usage notes: the term derives from fiacco, meaning weak or tired; close relatives include fiacchezza