Where does “tailfin” come from?

tailfin (English) comes from English fin, from English finasteride, from English -steride, from English -ide, from Middle French -ide, from Latin -is, from Latin -a, from Proto-Italic -ā.

tailfin (English): A fin at the tail of a fish, caudal fin; A fin on...

Definitions

  1. A fin at the tail of a fish, caudal fin; A fin on...

Ancestry of “tailfin”, step by step

tailfin traces back through two separate lines of ancestry.

via English fin

StepLanguageWordMeaning
1EnglishfinOne of the appendages of a fish, used to propel...
2EnglishfinasterideA medication used to treat male pattern baldness and benign prostatic hyperplasia in males
3English-sterideUsed to form names of [[w:5α-reductase
4English-ideAny of a group of related compounds - azide,...
5Middle French-ideid (dynast)
6Latin-issuffixed to the root of nouns in composition,...
7Latin-asuffixed to the roots of verbs, forms agent...
8Proto-ItalicForms masculine agent nouns from prefixed or compounded bases
9Proto-Indo-European-éh₂

via English Tail

StepLanguageWordMeaning
1EnglishTailA Chinese constellation coinciding with the tail of Scorpius, one of the 28 lunar mansions and the tail of Azure Dragon
2Middle EnglishtaylA tail; The back side or reverse of a creature; A...
3Old Englishtæġltail
4Proto-Germanictagląhair; ponytail; hair of a tail; tail
5Proto-Indo-Europeandoḱ-hair of the tail
6Proto-Indo-Europeandeḱ-take; perceive
Every word from Proto-Indo-European -éh₂
tailfin — Etymology, Origin & Word History | Etymology Explorer