Fifth
Quintara is a modern elaboration of the Latin root 'quintus', meaning fifth. It was historically used to denote the fifth child or a child born in the fifth month, though it is now chosen primarily for its rhythmic sound.
Less common today
Quintara isn't in the latest US Top 1000. It last peaked at #6,999 in 1994.
US births per 5-year period, 1990βpresent (SSA data).