What is another word for "medium"?

Roget's Thesaurus (1911) lists these synonyms for "medium": about, accoucheur, accoucheuse, agency, aid, all, along, ambient, anchor, and, another, any, around, assistance, atmosphere, average, balance, banlieue, begird, belt, beset, border, bow, capital, charmer, circle, circumambient, circumference, circumferential, circumfluent, circumjacence, circumjacent, circumscribe, circumvent, clairvoyant, clarity, clear, common, commonplace, compass.