knickers n.

"descendant of Dutch settlers of New York," 1831, from Diedrich Knickerbocker, the name under which Washington Irving published his popular "History of New York" (1809). The pen-name was borrowed from Irving's friend Herman Knickerbocker, and literally means "toy marble-baker," from German knicker, schoolboy slang for "marble," apparently an agent-noun from the imitative verb knikken "to snap."

also nicky tam, "garter worn over trousers," 1911, Scottish, from a shortened, colloquial form of knickers + Scottish & northern English dialect taum, from Old Norse taumr "cord, rein, line," cognate with Old English team, the root sense of which appears to be "that which draws" (see team (n.)). Originally a string tied by Scottish farmers around rolled-up trousers to keep the legs of them out of the dirt.