noun
Edo-period hired thief taker; private detective
Historical term for a civilian who assisted the authorities in catching criminals during the Edo period, often working on a commission basis. Similar to 目明かし and 御用聞き.
岡っ引きは江戸時代に犯罪者を捕まえるのを手伝った。
Okappiki helped catch criminals during the Edo period.
In period dramas, scenes of okappiki patrolling the town often appear.
The term likely derives from 岡 (hill, but here possibly a euphemism for 'unofficial' or 'outside') and 引く (to pull, to draw in), with the diminutive っ inserted. The exact origin is uncertain, but it refers to someone who 'pulls in' criminals from the shadows.