The headword -- presumably quoted from somewhere, but attested only here -- is the aorist active infinitive of the verb diekperdiki/zw. Its two prepositional prefixes, dia and ek, are reflected in the translation above.
For singly compound e)kperdiki/sai see epsilon 562, from Aristophanes, Birds 768. As regards diaperdiki/zw (attested in the aorist infinitive diaperdiki/sai in Hesychius delta1213 and Etymologicum Magnum 269.37, regarded as a context-less fragment of Attic comedy) LSJ s.v. claims the Suda's diekperdiki/zw as its equivalent, though that does less than full justice to the double compound.
For partridges cf. pi 1041, pi 1042.