The Collaborative International Dictionary of English v.0.48:

Vocable \Vo"ca*ble\, n. [L. vocabulum an appellation,
   designation, name, fr. vocare to call, fr. vox, vocis, a
   voice, a word: cf. F. vocable. See Voice.]
   A word; a term; a name; specifically, a word considered as
   composed of certain sounds or letters, without regard to its
   meaning.
   [1913 Webster]

         Swamped near to drowning in a tide of ingenious
         vocables.                                --Carlyle.
   [1913 Webster]

WordNet (r) 3.0 (2006):

vocable
    n 1: a word that is spoken aloud [syn: vocable, spoken word]

Moby Thesaurus II by Grady Ward, 1.0:

100 Moby Thesaurus words for "vocable":
   allophone, alveolar, antonym, apico-alveolar, apico-dental,
   articulation, aspiration, assimilation, bilabial, cacuminal,
   cerebral, check, consonant, continuant, dental, diphthong,
   dissimilation, epenthetic vowel, explosive, expression, free form,
   glide, glottal, glottalization, guttural, homograph, homonym,
   homophone, labial, labialization, labiodental, labiovelar,
   laryngeal, lateral, lexeme, lingual, linguistic act,
   linguistic form, liquid, locution, logos, manner of articulation,
   metonym, minimum free form, modification, monophthong,
   monosyllable, morphophoneme, mute, nasal, occlusive, palatal,
   parasitic vowel, parol, parole, peak, pharyngeal,
   pharyngealization, phonation, phone, phoneme, plosive,
   polysyllable, prothetic vowel, retroflex, segmental phoneme,
   semivowel, sequence of phonemes, sonant, sonority, speaking,
   speech act, speech sound, stop, string, surd, syllabic nucleus,
   syllabic peak, syllable, synonym, term, the spoken word, tongue,
   transition sound, triphthong, usage, utterance, utterance string,
   velar, verbalism, verbum, vocalic, vocoid, voice, voiced sound,
   voiceless sound, voicing, vowel, word, word of mouth