Of Greek consonants, neither aspirated nor voiced, as p, t, k
Of obstruents in other languages, not voiced, aspirated, glottalized, or otherwise different in phonation from the prototypical values of the voiceless IPA letters (p, t, k, f, θ, s, ʃ, etc.).
A tenuis consonant.
1887, Max Müller
thin, fine, slender