Pronunciation: (fôr'tis), [key]
—adj., n., pl. -tesPronunciation: (-tēz). [key] Phonet.
pronounced with considerable muscular tension and breath pressure, resulting in a strong fricative or explosive sound. In stressed position (p, t, k, ch, f, th, s, sh) and sometimes (h) are fortis in English as compared with (b, d, g, j, v, &thslash;, z, and zh), which are lenis. Cf. lenis.
a fortis consonant.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.