Where does “still” come from?

still (German) comes from Middle High German stille, from Old High German stillī, from Old High German -ī, from Proto-West Germanic -ī, from Proto-Germanic -į̄, from Proto-Indo-European -íh₂, from Proto-Indo-European -h₂ — Creates collective nouns, which refer to groups...

still (German): quiet, silent; quietly, silently