Where does “thirdhand” come from?

thirdhand (English) comes from English third, from Middle English thirde, from Old English þridda, from Proto-West Germanic *þriddjō, from Proto-Germanic þridjô, from Proto-Indo-European tretyós, from Proto-Indo-European tr̥tyós, from Proto-Indo-European tréyes — three.

thirdhand (English): Having been relayed by two intermediate sources;...

Definitions

  1. Having been relayed by two intermediate sources;...

Ancestry of “thirdhand”, step by step

thirdhand traces back through two separate lines of ancestry.

via English third

StepLanguageWordMeaning
1EnglishthirdThe ordinal form of the cardinal number three;...
2Middle Englishthirde
3Old Englishþriddathird
4Proto-West Germanic*þriddjōthird
5Proto-Germanicþridjôthird
6Proto-Indo-Europeantretyós
7Proto-Indo-Europeantr̥tyósthird
8Proto-Indo-Europeantréyesthree

via English Hand

StepLanguageWordMeaning
1EnglishHandThe part of the forelimb below the forearm or wrist in a human, and the corresponding part in many other animals
2Middle Englishhondhand; Alternative form of hound
3Old EnglishhandA hand
4Proto-West Germanichanduhand
5SwedishhandA hand; A hand; the set of cards held by a player
6Old SwedishhandA hand; A direction; A behalf
7Old Norsehǫndhand
8Proto-Germanichanduzhand
Every word from Proto-Indo-European tréyesEvery word from Proto-Indo-European tr̥tyósEvery word from Proto-Indo-European tretyós