taggha : [an affirmative particle] truly; surely; if it is so.

A.P. Buddhadatta Mahathera, Concise Pali-English and English-Pali Dictionary [available as digital version from Metta Net, Sri Lanka]

Taggha [tad+gha, cp. in -- gha & Lat. ec -- ce ego -- met, Gr. e)gw/ -- ge] affirmative particle ("ekaŋsena" DA i.236; ekaŋsa -- vacana J v.66; ekaŋse nipāta J v.307): truly, surely, there now! Vin ii.126, 297; D i.85; M i.207, 463; iii.179; J v.65 (v. l. tagghā); Sn p. 87.

Pali-English Dictionary, TW Rhys Davids, William Stede,