A திரிசொல் type: a single drifted literary word that can express several different meanings depending on context.

வரைந்தான் can mean "he wrote", "he married", "he defined", or "he departed" - the same word, four unrelated-looking meanings, depending entirely on the sentence around it.

வரைந்தான் - can mean "wrote", "married", "defined", or "departed".