lene

noun2

1. •
   A voiceless, or unaspirated, stopped consonant, such as Greek pi, kappa, or tau.

   • When in a crasis, a lene consonant […] is combined with an aspirated vowel, the lene is always changed (except in the Ionic dialect) into the corresponding aspirate […] — 1861
2. •
   The smooth breathing (spiritus lenis).