Entry 2 senses · 2 variants Webster, 1913 Runlet · Run·let · IPA n. n. 01 n. A little run or stream; a streamlet; a brook. 1. A little run or stream; a streamlet; a brook. “To trace out to its marshy source every runlet that has cast in its tiny pitcherful with the rest.” — Lowell. 02 n. Same as Rundlet. 1. Same as Rundlet. See: Rundlet