[1] The primary headword (which must be quoted from somewhere) is the perfect active participle, masculine nominative singular, of the verb diarrh/gnumi (LSJ entry at web address 1). In the perfect the active forms take on a passive meaning. See e.g. dierrwguiw=n in Plato, Phaedo 86A (web address 2) or dierrw/gesan in Appian, Civil Wars 4.10 (web address 3). (For an example of a perfect passive form see Josephus, Jewish War 2.322, at web address 4.)
[2] Masculine accusative singular or neuter nominative/accusative plural (probably the latter: cf. lambda 53, rho 28) of the headword. Again, it must be quoted from somewhere -- perhaps the Septuagint: 2 Kingdoms 1.2. Hesychius delta1648 has dierrwgo/ta glossed with diesxisme/na; cf. Latte ad loc., '1 Regn. 4.12 [actually dierrhgo/ta there: DW] ...'.