DETERIORATE most nearly means:

DETERIORATE means to become progressively worse; to decline in quality or condition. Example: 'Her health began to deteriorate after the accident.' From Latin 'deteriorare' (to make worse), from 'deterior' (worse). Synonyms: decline, worsen, degenerate, decay, degrade, depreciate, regress. Antonyms: improve, enhance, ameliorate, recover, restore, upgrade. Related: DETERIORATION (noun — the process or state of deteriorating). Don't confuse with: DETER (to discourage); DETERMINE (to decide). Health and condition vocabulary on the ASVAB: DETERIORATE (decline), DECAY (rot or decline), DEGENERATE (decline in physical or moral condition), DECOMPOSE (break down chemically or biologically), CORRODE (gradually destroy by chemical action, especially metal), ERODE (gradually destroy by wearing away — water on rock, for instance), DEPRECIATE (decline in value or price). These words all relate to a decline from a previous state — the ASVAB tests the precise shade of meaning each carries.