Definition of through-bore in US English:

through-bore

verb

rare
  • with object To bore through, perforate.

Origin

Old English; earliest use found in Alexander's Letter to Aristotle. Cognate with or formed similarly to West Frisian trochboarje, Middle Dutch dōrebōren (Dutch doorboren), Middle Low German dörchbōren, Old High German duruhborōn (Middle High German durchborn, German durchbohren) from the Germanic base of through- + the Germanic base of bore.

Pronunciation

through-bore

/ˌθruːˈbɔː/