The story
- Proto-Indo-European*h₁én
- Proto-Italic*en
- Proto-Italic*en-
- Latinin-
- Proto-Indo-European*bʰer-
- Proto-Indo-European*bʰéreti
- Proto-Italic*ferō
- Latinferō
- Latinīnferō
- Latinīnfrā
- Englishinfra-
- Proto-Indo-European*upó
- Proto-Italic*supo
- Latinsub
- Latinsub-
- Englishsub-
- Old Frenchspecifique
- Englishspecific
- Englishsubspecific
- English todayinfrasubspecific
From infra- + subspecific.
Etymology from Wiktionary, CC BY-SA 4.0.