The two glosses make a distinction between a passive "goad-struck" (i.e. someone deserving torture, like ke/ntrwn, kappa 1344), and an active "goad-striker" (e.g. charioteer); these should be distinguished by accent (kentro/tupos vs. kentrotu/pos, LSJ s.v.), although the distinction is often effaced in Byzantine Greek.
1Gloss from Hesychius kappa2234 and Photius kappa571 Theodoridis (with paroxytone lemma). The word also appears in kappa 1344. The Etymologicum Gudianum glosses the similar kentro/tupton as "someone deserving whipping" (mastigi/as). The only literary instance is Libanius, Letters 226.5: "a knavish and goad-struck little man attacked the orator"; the lexicographers' gloss "knavish" could well be from that context. Greek Anthology 9.543 (Philip) uses the similar kentrotuph/s as "goad-struck", referring to colts.↩
2From the scholia on Aristophanes, Clouds 450 (repeated in kappa 1344), glossing ke/ntrwn "rogue, someone tortured with a goad": "insofar as we call charioteers goad-strikers, as they strike horses with goads".