undermost

of, relating to, or located at the bottom <the undermost layer of the mattress filling should provide firm back support> Synonyms bottommost, low, lowermost, nethermost, rock-bottom, bottomRelated Words below, lower, low-grade, lowly, nether, under; lowered, low-lying, sunkenNear Antonyms higher, loftier, upper; elevated, escalated, heightened, jacked (up), lifted, raised, uplifted, upraisedAntonyms highest, loftiest, top, topmost, upmost, uppermost