Where does “tromdacht” come from?

tromdacht (Old Irish) comes from Old Irish tromda, from Old Irish trom, from Proto-Celtic trummos, from Proto-Indo-European trewd- — to push, to thrust.

Ancestry of “tromdacht”, step by step

Step	Language	Word	Meaning
1	Old Irish	tromda	oppressive, importunate; heavy, sad, weighty,...
2	Old Irish	trom	heavy; heavy, severe, grievous, difficult; sad,...
3	Proto-Celtic	trummos	heavy
4	Proto-Indo-European	trewd-	to push, to thrust

Every word from Proto-Indo-European trewd- →Every word from Proto-Celtic trummos →Every word from Old Irish trom →