noun, feminine/as.te.ni/plural: asthénies
asthénie is feminine in French.
asthenia (loss of strength)
Related: neurasthénie
Borrowed from Ancient Greek ἀσθένεια (asthéneia), from ἀσθενής (asthenḗs, “sick, weak”), from ἀ- (a-, “not, un-”) + σθένος (sthénos, “strength”).