Consonant

Con"so*nant\, n. [L. consonans, -antis.] An articulate sound which in utterance is usually combined and sounded with an open sound called a vowel; a member of the spoken alphabet other than a vowel; also, a letter or character representing such a sound.

Note: Consonants are divided into various classes, as mutes, spirants, sibilants, nasals, semivowels, etc. All of them are sounds uttered through a closer position of the organs than that of a vowel proper, although the most open of them, as the semivowels and nasals, are capable of being used as if vowels, and forming syllables with other closer consonants, as in the English feeble (-b'l), taken (-k'n). All the consonants excepting the mutes may be indefinitely, prolonged in utterance without the help of a vowel, and even the mutes may be produced with an aspirate instead of a vocal explosion. Vowels and consonants may be regarded as the two poles in the scale of sounds produced by gradual approximation of the organ, of speech from the most open to the closest positions, the vowel being more open, the consonant closer; but there is a territory between them where the sounds produced partake of the qualities of both.

Note: "A consonant is the result of audible friction, squeezing, or stopping of the breath in some part of the mouth (or occasionally of the throath.) The main distinction between vowels and consonants is, that while in the former the mouth configuration merely modifies the vocalized breath, which is therefore an essential element of the vowels, in consonants the narrowing or stopping of the oral passage is the foundation of the sound, and the state of the glottis is something secondary." --H. Sweet.