Where does “smart” come from?

smart (Proto-Germanic) comes from Proto-Germanic smertaną, from Proto-Indo-European (s)merd- — to bite, to sting.

Ancestry of “smart”, step by step

StepLanguageWordMeaning
1Proto-Germanicsmertanąto hurt
2Proto-Indo-European(s)merd-to bite, to sting
Every word from Proto-Indo-European (s)merd- →Every word from Proto-Germanic smertaną →