slim adj.

1650s, "thin, slight, slender," usually with suggestion of gracefulness, from Dutch slim "bad, sly, clever," from Middle Dutch slim "slanting, crooked; bad, wrong," from Proto-Germanic *slembaz "oblique, crooked" (source also of Middle High German slimp "slanting, awry," German schlimm "bad, cunning, unwell"), which is of unknown origin. Italian sghembo "crooked, slanting, lopsided" is from Germanic.

Not found in Middle English. The Germanic sense evolution seems to be "slanting" to "slight, insignificant" then "gracefully slender." Down another path, "slanting" to "crooked" to "bad, sick, wrong."

Of chances, etc., "meager, small" from 1670s. The sense of "slight, flimsy, unsubstantial" is by 1813, of fabric. In English 17c. also sometimes in reference to persons with a sense "sly, cunning, crafty." Related: Slimly; slimness.

With obsolete extended adjectival forms slimsy "flimsy, unsubstantial" (1845, American English, of fabric, etc.); slimikin "small and slender" (1745). Slim Jim attested from 1887 in sense of "very thin person;" from 1902 as a type of slender cigar; from 1975 as a brand of meat snack. Slim volume "book of verse by a little-known or aspiring poet" is by 1920.

1808 [Jamieson], "to scamp one's work, do carelessly or superficially," from slim (adj.). The meaning "to make slim" (a garment, etc.) is from 1862; that of "reduce (one's) weight" is from 1930. Related: Slimmed; slimming. Adjectival phrase slimmed-down is attested by 1946 in advertisements, from the verbal phrase.