Source : Webster's Revised Unabridged Dictionary (1913)

Prenominal \Pre*nom"i*nal\, a.
   Serving as a prefix in a compound name. --Sir T. Browne.

Source : WordNet®

prenominal
     adj : of adjectives; placed before the nouns they modify; "`red'
           is an attributive adjective in `a red apple'" [syn: {attributive}]
           [ant: {predicative}]