Where does “decke” come from?

decke (German) comes from Middle High German decke, from Old High German theckī, from Old High German thecken, from Proto-West Germanic þakkjan, from Proto-Germanic þakjaną, from Proto-Germanic þaką, from Proto-Indo-European (s)teg- — to cover; pole, stick, beam.

decke (German): present first-person singular of decken "I cover"