英语词源字典 - 在线词源网站

boot-licker (n.): also bootlicker, "toady, servile follower," 1846, from boot (n.1) + agent noun from lick (v.). Foot-licker in the same sense is from 1610s.
flicker (n.1): 1849, "wavering, unsteady light or flame;" 1857 as "a flickering," from flicker (v.).
flicker (v.): Old English flicorian "to flutter, flap quickly and lightly, move the wings," originally of birds. Onomatopoeic and suggestive of quick motion. Sense of "shine with a wavering light" is c. 1600, but not common till 19c. Related: Flickered; flickering.
flicker (n.2): type of North American woodpecker, 1808, American English, said to be echoic of bird's note, or from black spots on plumage of the underparts that seem to flicker as it flits from tree to tree.
lickerish (adj.): "fond of delicious fare," c. 1500, from Middle English likerous "pleasing to the palate" (late 13c.), from Anglo-French *likerous, Old French licherous (see lecherous). Unlike the French word, it generally kept close to its literal sense.
slicker (n.): 1851, "tool for smoothing leather," from slick (v.). Meaning "waterproof raincoat" is from 1884; sense of "clever and crafty person" is from 1900.