fortisn.adj.

1889 J. Cundill Dict. Explosives 11 Glycero-Nitre... This explosive has been submitted for authorisation in this country under the name of ‘Fortis’.

1909 Webster's New Internat. Dict. Eng. Lang. Fortis a.

1932 G. K. Zipf Sel. Stud. Rel. Frequency in Lang. i. 4 The fortis tenuis aspirata is decidedly more conspicuous than the faint lenis media.

1933 L. Bloomfield Lang. vi. 99 In English the unvoiced stops are aspirated fortes.

1962 A. C. Gimson Introd. Pronunc. Eng. iv. 32 A voiceless/voiced pair such as [s, z] are distinguished not only by the presence or absence of voice but also by the degree of breath and muscular effort involved in the articulation... Those English consonants which are usually voiced tend to be articulated with relatively weak energy, whereas those which are always voiceless are relatively strong. Thus, it may be important to define [s]..as strong or fortis and [z] as weak or lenis.

1964 Jakobson & Halle in D. Abercrombie et al. Daniel Jones 100 The distinctive mark in a fortis-lenis pair.

1965 Language 41 480 The stop is of greater duration and fortis articulation.

1969 Jrnl. Lancs. Dial. Soc. 14 The weakening of the fortis consonants in Jestetten was a phonetic change which threatened the stability of the whole consonant system.