weak acid
Chemistry term for an acid that only partially dissociates in solution. Contrasts with 強酸 (strong acid).
Acetic acid is a type of weak acid.
Compound of 弱 (じゃく, 'weak') + 塩酸 (えんさん, 'acid'). The reading じゃく for 弱 is the on'yomi used in technical compounds.