Source : Webster's Revised Unabridged Dictionary (1913)

Consonantal \Con`so*nan"tal\, a.
   Of the nature of a consonant; pertaining to consonants.

Source : WordNet®

consonantal
     adj 1: being or marked by or containing or functioning as a
            consonant; "consonantal sounds"; "a consonantal Hebrew
            text"; "consonantal alliteration"; "a consonantal
            cluster" [ant: {vocalic}]
     2: relating to or having the nature of a consonant
     3: of liquids and nasals [syn: {nonsyllabic}, {nonvocalic}]
        [ant: {vocalic}]