The Oxford Thesaurus An A-Z Dictionary of Synonyms - weakenv.

1) debilitate, enfeeble, enervate, emasculate, mitigate, moderate, dilute, deplete, diminish, lessen, depress, lower, reduce, sap, undermine, exhaust, impoverish: The continuous torture helped to weaken Errol's resolve. 2) fade, dwindle, tire, droop, sag, fail, give way, crumble, flag: My determination weakened when I saw what had happened to the children. 3) give in, relent, acquiesce, give way, yield, accede, consent, agree, assent, soften, bend, ease up, let up, ease off, relax: If you ask very politely, she might weaken and allow you to go out and play. 4) water (down) , dilute, thin (out) : Adding the water so weakened the soup that it tasted like dishwater.