Merriam-Webster's Collegiate® Dictionary, 11th Edition
CONSONANT
I. adjective see: sound
Date: 15th century
being in agreement or harmony ; free from elements making for discord, marked by musical consonances, having similar sounds , relating to or exhibiting consonance ; resonant , consonantly adverb
II. noun
Etymology: Middle English, from Anglo-French, from Latin consonant-, consonans, from present participle of consonare
Date: 14th century
one of a class of speech sounds (as \\p\\, \\g\\, \\n\\, \\l\\, \\s\\, \\r\\) characterized by constriction or closure at one or more points in the breath channel