Persistent

a.	1.	Inclined to persist; having staying qualities; tenacious of position or purpose.
	2.	(Biol.) Remaining beyond the period when parts of the same kind sometimes fall off or are absorbed; permanent; as, persistent teeth or gills; a persistent calyx; - opposed to deciduous, and caducous.

Adj.	1.	persistent - never-ceasing; "the relentless beat of the drums" Synonyms: relentless, unrelenting
	2.	persistent - continually recurring to the mind; "haunting memories"; "the cathedral organ and the distant voices have a haunting beauty"- Claudia Cassidy Synonyms: haunting
	3.	persistent - retained; not shed; "persistent leaves remain attached past maturity"; "the persistent gills of fishes" Synonyms: lasting Antonyms: caducous, shed - shed at an early stage of development; "most amphibians have caducous gills"; "the caducous calyx of a poppy"

persistent - persistence

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