muster (n.)youdaoicibaDictYouDict[muster 词源字典]
late 14c., "action of showing, manifestation," from Old French mostre "illustration, proof; examination, inspection" (13c., Modern French montre), literally "that which is shown," from mostrer (see muster (v.)). Meaning "act of gathering troops" is from c. 1400. To pass musters (1570s) originally meant "to undergo military review without censure."[muster etymology, muster origin, 英语词源]
tank (v.)youdaoicibaDictYouDict
1900, "to put into a tank," from tank (n.). Meaning "to lose or fail" attested from 1976, originally in tennis jargon, specifically in an interview with Billie Jean King in "Life" magazine, Sept. 22, 1967:
"When our men don't feel like trying," she says, "They 'tank' [give up]. I never tanked a match in my life and I never saw a girl do it. The men do it all the time in minor tournaments when they don't feel like hustling. You have to be horribly competitive to win in big-time tennis."
Sometimes said to be from boxing, in some sense, perhaps from the notion of "taking a dive," but evidence for this is wanting. Related: Tanked; tanking. Adjective tanked "drunk" is from 1893.