'sweat-soaked' is a modern English compound formed from the noun 'sweat' and the adjective (past-participle) 'soaked'. 'sweat' originates from Old English 'swāt', where Proto-Germanic '*swait-' meant 'sweat'; 'soaked' comes from Old English 'sōcian'/'sōc' (via Middle English 'soken'), where the root meant 'to soak or be thoroughly wet.'

'sweat' existed in Old English as 'swāt' and remained semantically stable; 'soak' developed through Old English and Middle English forms like 'sōcian'/'soken' and the past participle 'soaked' was used to describe something made thoroughly wet. The compound 'sweat-soaked' emerged in Modern English by combining these elements to describe being drenched in sweat.

Initially both elements carried literal senses related to moisture ('sweat' = bodily moisture; 'soaked' = thoroughly wet). When compounded, the meaning remained literal: 'thoroughly wet with sweat,' and that core meaning persists in modern usage.