The Collaborative International Dictionary of English v.0.48:

Fricative \Fric"a*tive\, a. [See Frication.] (Phon.)
   Produced by the friction or rustling of the breath, intonated
   or unintonated, through a narrow opening between two of the
   mouth organs; uttered through a close approach, but not with
   a complete closure, of the organs of articulation, and hence
   capable of being continued or prolonged; -- said of certain
   consonantal sounds, as f, v, s, z, etc. -- n. A fricative
   consonant letter or sound. See Guide to Pronunciation,
   [sect][sect] 197-206, etc.
   [1913 Webster]

WordNet (r) 3.0 (2006):

fricative
    adj 1: of speech sounds produced by forcing air through a
           constricted passage (as `f', `s', `z', or `th' in both
           `thin' and `then') [syn: fricative, continuant,
           sibilant, spirant, strident]
    n 1: a continuant consonant produced by breath moving against a
         narrowing of the vocal tract [syn: fricative consonant,
         fricative, spirant]