protuberant (adj.)

1640s, from French protubérant (16c.) and directly from Late Latin protuberantem (moninative protuberans), present participle of protuberare "to swell, bulge, grow forth," from Latin pro "forward" (see pro-) + tuber "lump, swelling" (from PIE root *teue- "to swell"). Related: Protuberantly.