"gaze intently," early 13c., of unknown origin, with no obvious corresponding word in Old French. Perhaps from Old English *purian, suggested by spyrian "to investigate, examine," and spor "a trace, vestige." Related: Pored; poring.
"minute opening," late 14c., from Old French pore (14c.) and directly from Latin porus "a pore," from Greek poros "a pore," literally "passage, way," from PIE *poro- "passage, journey," suffixed form of PIE root *per- (2) "to lead, pass over."