subindex
Sub*in"dex, n.; pl. Subindices (. (Math.) Defn: A number or mark placed opposite the lower part of a letter or symbol to distinguish the symbol; thus, a0, b1, c2, xn, have 0, 1, 2, and n as subindices.
Sub*in"dex, n.; pl. Subindices (. (Math.) Defn: A number or mark placed opposite the lower part of a letter or symbol to distinguish the symbol; thus, a0, b1, c2, xn, have 0, 1, 2, and n as subindices.