Where does “þráðnykra” come from?

þráðnykra (Icelandic) comes from Icelandic þráður, from Old Norse þráðr, from Proto-Germanic þrēduz, from Proto-Indo-European treh₁-tu-, from Proto-Indo-European terh₁- — to rub, turn; to drill, pierce.

þráðnykra (Icelandic): slender-leaf pondweed (Stuckenia filiformis, syn. Potamogeton filiformis)

Definitions

  1. slender-leaf pondweed (Stuckenia filiformis, syn. Potamogeton filiformis)

Ancestry of “þráðnykra”, step by step

þráðnykra traces back through two separate lines of ancestry.

via Icelandic þráður

StepLanguageWordMeaning
1Icelandicþráðurstring, strand, thread; fibre; thread
2Old Norseþráðrthread; past participle of þreyja; past...
3Proto-Germanicþrēduzthread, twisted fibre
4Proto-Indo-Europeantreh₁-tu-
5Proto-Indo-Europeanterh₁-to rub, turn; to drill, pierce

via Icelandic nykra

StepLanguageWordMeaning
1Icelandicnykrapondweed plant of the genus
2Icelandicnykura water-demon, the nixie, the nick
3Old Norsenykra water-demon, the nixie, the nick; mostly appearing as a grey horse-like creature with inverted hoofs and forward fetlocks that emerges from lakes
4Proto-Germanicnikwiz-
5Proto-Indo-Europeanneygʷ-to wash
Every word from Proto-Indo-European terh₁-Every word from Proto-Indo-European treh₁-tu-Every word from Proto-Germanic þrēduz