The Proto-Turkic word *appa
Word *appa
Meaning father
Synonyms *ata / ete

Comments
S. A. Starostin, A. V. Dybo, O. A. Mudrak - An Etymological Dictionary of Altaic Languages, 2003, Brill

Other words that might be of interest
*kɨ̅ŕ ‘girl’, *öd- ‘lust, sexual passion’, *iāka ‘elder’, *dāj- ‘uncle’, *ēr ‘man’, *ẹrkek ‘man, husband, male’, *ana / eńe ‘mother’, *apa ‘mother, elder sister, aunt’, *eren ‘man, mankind’, *ogul ‘son’, *diĺi ‘female, woman’, *eme ‘female, old woman’, *urag- ‘female’, *bāl- ‘young animal, child, younger relative’