"birthday"
Latin, an Indo-European language last time I checked, has dies natalis, literally 'natal day'. Natalicium, an adjectival form of natalis 'birth' means 'birthday present'. Classical Greek cut to the chase and simply used ημερα (hēmera) 'day' for 'birthday'. They also used ta genesia, literally 'the natal (thing)' for 'the day kept in memory of the birthday of the dead'. (Cf. Koine Greek in Matt. xiv.6 γενεσίοις δὲ γενομένοις τοῦ Ἡρῴδου ὠρχήσατο ἡ θυγάτηρ τῆς Ἡρῳδιάδος ἐν τῷ μέσῳ καὶ ἤρεσεν τῷ Ἡρῴδῃ, die autem natalis Herodis saltavit filia Herodiadis in medio et placuit Herodi (Vulgate), But when Herod's birthday was kept, the daughter of Herodias danced before them, and pleased Herod (KJV).) Czech has narozeniny, literally 'natal', as well as datum narození 'birth date' and den narození 'birth day'.
