bustling (adj.)

"be active in a noisy and agitated way," 1570s (bustling "noisy or excited activity" is from early 15c.), of uncertain origin, perhaps a frequentative of Middle English bresten "to rush, break," from Old English bersten (see burst (v.)), influenced by Old Norse buask "to make oneself ready" (see busk (v.)). Or it might be from busk (v.) via a 16c. frequentative form buskle. Related: Bustled; bustling; bustler.