Where does “штил” come from?

штил (Serbo-Croatian) comes from German Stiel, from Middle High German stil, from Old High German stil, from Latin stilus, from Proto-Indo-European (s)teyg- — to be sharp; to sting.

Definitions

Ancestry of “штил”, step by step

Step	Language	Word	Meaning
1	German	Stiel	stalk; a long, fairly thin protrusion, e.g. the...
2	Middle High German	stil	—
3	Old High German	stil	—
4	Latin	stilus	A pointed instrument; stake, pale, spike; A...
5	Proto-Indo-European	(s)teyg-	to be sharp; to sting

Every word from Proto-Indo-European (s)teyg- →Every word from Latin stilus →Every word from Old High German stil →