The word 'write-up' is a modern English compound noun formed from the phrasal verb 'to write up'. The verb 'write' descends from the Proto-Germanic wrītaną, which originally meant "to tear, scratch, carve," reflecting the early methods of inscribing runes on wood or stone. The particle 'up' is used in its completive sense, common in Germanic languages, to signify bringing an action to a finished or public state. Thus, the literal combination "to write something up" evolved from the idea of completing a written account. By the early 20th century, this verbal phrase solidified into the noun 'write-up', specifically denoting a finalized, often formal or published, written report or review.

Structure: write (to form letters/words) + up (completive particle) write: From Old English wrītan (to score, outline, draw, write), of Germanic origin. Functional role: The core verb, providing the action of producing text. up: From Old English up, upp, of Germanic origin. Functional role: An adverbial particle used phrasally to indicate completion, thoroughness, or finalization.