English dictionary
subindex
Definitions, examples, synonyms and antonyms from WordNet 3.0.
noun
-
A number or mark placed opposite the lower part of a letter or symbol to distinguish the symbol; thus, <i>a</i><subs>0</subs>, <i>b</i><subs>1</subs>, <i>c</i><subs>2</subs>, <i>x</i><subs>n</subs>, have 0, 1, 2, and <i>n</i> as <i>subindices</i>.
Source: webster1913