We don't have synonyms for pongal yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are ponga, pongas and pontal.
(n) :
A Hindu harvest festival of South India, particularly in the Tamil community, observed at the start of the month Tai (typically around January 14).
(n) :
A Hindu harvest festival of South India, particularly in the Tamil community, observed at the start of the month Tai (typically around January 14).