What is another word for "sub"?

Roget's Thesaurus (1911) lists these synonyms for "sub": about, aerial, aeriform, aerography, aerology, aerometer, aerometry, aeronaut, aeronautics, aeroscope, aeroscopy, aerosphere, aerostation, air, airy, all, and, aneroid, anger, animus, any, around, atmosphere, atmospheric, avenge, avengeance, avengement, avenger, awful, back, balance, barometer, baroscope, bear, become, belle, below, better, blood, blue.