unleavenable

Etymology tree
Proto-Indo-European *né
Proto-Indo-European *n̥-
Proto-Germanic *un-
Proto-West Germanic *un-
Old English un-
Middle English un-
English un-
Proto-Indo-European *h₁lengʷʰ-
Proto-Indo-European *-us
Proto-Indo-European *h₁léngʰusder.
▲
Proto-Italic *breɣʷisinflu.?
Proto-Italic *leɣʷis
Latin levis
Proto-Indo-European *-h₂
Proto-Indo-European *-éh₂
Proto-Indo-European *-yéti
Proto-Indo-European *-eh₂yéti
Proto-Italic *-āō
Latin -ō
Latin levō
Proto-Indo-European *-mn̥
Proto-Italic *-mn̥
Latin -men
Vulgar Latin *levāmender.
Old French levainbor.
Middle English levayn
English leaven
Proto-Indo-European *-tḗr
Proto-Indo-European *-dʰlom
Proto-Indo-European *-dʰlis
Proto-Italic *-ðlis
Latin -bilis
Latin -ābilis
Old French -ablebor.
Middle English -able
English -able
English unleavenable
From un- + leaven + -able.