'agrypnia' originates from Greek, specifically the word 'ἀγρυπνία' (agrypnia), where 'ἀ-' meant 'not' and 'ὕπνος' (hypnos) meant 'sleep'.

'ἀγρυπνία' transformed into the Latin word 'agrypnia', and eventually became the modern English word 'agrypnia'.

Initially, it meant 'lack of sleep', and this meaning has largely remained the same in modern usage.