OTCi
Otci is a grammatical form of the Czech noun otec, which means father. In Czech, otci can function as the dative singular (to the father) and as the locative singular after the preposition o, meaning “about the father.” For example, poslal jsem dopis otci (I sent a letter to the father) and mluvím o otci (I am talking about the father). It is not a standalone lexical item but a case form used to indicate grammatical roles in sentences.
Etymology and relatives: the word otec derives from the Proto-Slavic root *otьcь, related to the concept of
Usage notes: otci is appropriate in contexts requiring a direct reference to a specific father in indirect
See also: Czech grammar, otec (father), Czech noun declension, Slavic etymology.