The headword, presumably extracted from the quotation given, is the present middle/passive participle, masculine nominative singular, of the verb paraba/llw, I throw beside; see also pi 270, pi 271, pi 272, pi 273, pi 275, pi 276, pi 277, pi 279, pi 280, pi 281, pi 513, and generally LSJ s.v.
[1] Adler identified the quotation as John of Antioch fr.170 (FHG 4.603), now 254 Roberto (= Constantine VII Porphyrogenitus, De virtutibus et vitiis [On Virtues and Vices] 1.197.19-21); cf. generally beta 246. The individual concerned, unidentifiable, appears to be a king or emperor who began well but went to the bad.