渎 by itself is rarely used alone in modern Chinese. It almost always appears in compounds: 亵渎 (to blaspheme/desecrate), 渎职 (dereliction of duty), 冒渎 (to disrespect). The standalone 渎 in the literary sense of 'ditch' is archaic.
memory
The character has the water radical 氵 (indicating the original 'waterway/ditch' meaning) plus 卖 (to sell) — something once pure, now debased — giving the sense of desecration.
