Where does “terskel” come from?
terskel (Norwegian Bokmål) comes from Old Norse þreskǫldr, from Proto-Germanic þreskwaþluz, from Proto-Germanic þreskaną, from Proto-Indo-European terh₁- — to rub, turn; to drill, pierce.
terskel (Norwegian Bokmål): a threshold; a sill
Ancestry of “terskel”, step by step