Where does “thyr” come from?

thyr (Old Danish) comes from Old Norse þurr, from Proto-Germanic þursuz, from Proto-Indo-European ters- — dry.

Ancestry of “thyr”, step by step

StepLanguageWordMeaning
1Old Norseþurrdry
2Proto-Germanicþursuzdry, lacking water
3Proto-Indo-Europeanters-dry
Every word from Proto-Indo-European ters- →Every word from Proto-Germanic þursuz →Every word from Old Norse þurr →