Meaning

noun large brown seaweeds having fluted leathery fronds

originInherited from Middle English *kelpe, culpe, *kilpe (Early Modern English kilpe), of unclear origin, though the attested forms point to Old English *cylp, possibly from Proto-West Germanic *kulpi, from Proto-Germanic *kulpiz (“lump, boll”, referencing the airsacks of species such as bladderwrack and knotweed), potentially a substrate term connected to Latin globus (“globe”) and Proto-Germanic…

Etymology from Wiktionary, CC BY-SA 3.0