Where does “perterebrāns” come from?

perterebrāns (Latin) comes from Latin terebro, from Latin terebra, from Latin -bra, from Proto-Indo-European -dʰrom — Alternative form of *-trom; instrumental suffix.

Ancestry of “perterebrāns”, step by step

Step	Language	Word	Meaning
1	Latin	terebro	I bore through, pierce, perforate
2	Latin	terebra	an instrument for boring; borer; gimlet;...
3	Latin	-bra	nominative neuter plural of -brum; accusative...
4	Proto-Indo-European	-dʰrom	Alternative form of *-trom; instrumental suffix

Every word from Proto-Indo-European -dʰrom →Every word from Latin -bra →Every word from Latin terebra →