Meaning

noun southeastern Asian tree producing large fruits resembling grapefruits

noun large pear-shaped fruit similar to grapefruit but with coarse dry pulp

originOf uncertain etymology, though possibly a variant of earlier pampelmoes, from French, Dutch, Portuguese sources ultimately equivalent to "thick lemon" or transcribing the Tamil பம்ப ளிமாசு (pampa ḷimācu, “big citrus”). Alternatively, possibly from pome (“apple”) + melon or some cognate; though such a compound is currently unattested, some early variant spellings seem to show influence from pome.

Etymology from Wiktionary, CC BY-SA 3.0