Entry 1 sense Webster, 1913 Oarsweed /(ōr"wēd`)/ · Oars·weed · IPA 01 n. Any large seaweed of the genus Laminaria; tangle; kelp. See Kelp. 1. Any large seaweed of the genus Laminaria; tangle; kelp. See Kelp.(Bot.) See: Kelp