丂 pictures breath that cannot rise freely and is not used as a standalone word today. It appears as a building element in 考 (to test / examine), 巧 (skilful), and 号 (number / to call out).
register
Archaic. You meet 丂 only inside other characters and in component breakdowns, never in speech.
Components
ideograph
丂kǎo
obstructed breath
An abstract figure of breath blocked on its way up — one horizontal then a bent rising stroke. A pure symbol, not decomposable into smaller parts.
Filed under radical 一 (yī, #1) by convention. 一 is not a separate component in 丂, so no strokes are highlighted.
