definition of
fricative

[1] #1 fricative n. [fricative consonant, spirant] a continuant consonant produced by breath moving against a narrowing of the vocal tract. wn

[2] #2 fricative s. [continuant, sibilant, spirant, strident] of speech sounds produced by forcing air through a constricted passage (as 'f', 's', 'z', or 'th' in both 'thin' and 'then'). wn