And more so because I plied the same trade as Llewyn Davis for a while.
"work with, use," late 14c., shortened form of applien "join to, apply" (see apply). The core of this is Latin plicare "to lay, fold, twist," from PIE root *plek- "to plait, twist" (cf. Greek plekein "to plait, twine," plektos "twisted;" Latin plectere (past participle plexus) "to plait, braid, intertwine;" Old Church Slavonic plesti "to braid, plait, twist;" Gothic flahta "braid;" Old English fleax "cloth made with flax, linen").
Sense of "travel regularly" is first 1803, perhaps from earlier sense "steer a course" (1550s). Related: Plied; plies; plying.
"to bend," late 14c., plien, from Old French plier, earlier pleier "to fold, bend," from Latin plicare "to lay, fold, twist" (see ply (v.1)). Related: Plied; plies; plying.