invalid

adj. 无效的；有病的；残废的

n. 病人；残废者

vt. 使伤残；使退役

vi. 变得病弱；因病而奉命退役

中文词源

invalid 无效的

in-,不，非，valid,有效的。

invalid: invalid: see valid
invalid (adj.1): "not strong, infirm," 1640s, from Latin invalidus "not strong, infirm, weak, feeble," from in- "not" (see in- (1)) + validus "strong" (see valid). Specific meaning "infirm from sickness, disease, or injury" is from 1640s.
invalid (adj.2): "of no legal force," 1630s, from special use of Latin invalidus (see invalid (adj.1)).
invalid (n.): 1709, originally of disabled military men, from invalid (adj.1). Invalides is short for French Hôtel des Invalides, home for old and disabled soldiers in the 7th arrondissement of Paris.

1、val- "be strong" + -id.2、含义：strong, effective, having force in law, legally binding, supported by facts or authority.3、in- "not" + valid.

1. Margaret resides with her invalid mother in a London suburb.: 玛格丽特同她病弱的母亲住在伦敦郊区。

2. At best Nella would be an invalid; at worst she would die.: 内拉往好里说会落下残疾，往坏处说可能会生命不保。

3. The treaty was declared invalid because it had not been ratified.: 条约没有得到批准，因此被宣布无效。

5. Dr. Smith looked in on the invalid the day before yesterday.: 史密斯大夫前天去看望那个病人.