The Collaborative International Dictionary of English v.0.48:

Indicant \In"di*cant\, a. [L. indicans, p. pr. indicare. See
   Indicate.]
   Serving to point out, as a remedy; indicating.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Indicant \In"di*cant\, n.
   That which indicates or points out; as, an indicant of the
   remedy for a disease.
   [1913 Webster]

WordNet (r) 3.0 (2006):

indicant
    n 1: something that serves to indicate or suggest; "an
         indication of foul play"; "indications of strain";
         "symptoms are the prime indicants of disease" [syn:
         indication, indicant]
    2: a number or ratio (a value on a scale of measurement) derived
       from a series of observed facts; can reveal relative changes
       as a function of time [syn: index, index number,
       indicant, indicator]