I. -nt adjective
Etymology: Latin persistent-, persistens, present participle of persistere to persist — more at persist
1.
a. : continuing in a course of action without regard to opposition or previous failure : tenacious of position or purpose : inclined to persist
persistent in good works
this persistent suitor
a persistent effort
b. : continuing to exist in spite of interference or treatment
a persistent cancer
: tending to recur
a persistent cough
2. : existing for a long or longer than usual time or continuously : enduring , lingering
a persistent odor of boiling cabbage
as
a.
(1) of a plant corolla : retained beyond the period of anthesis — opposed to caducous
(2) of a leaf : clinging all winter even though withered
some oaks and beeches have persistent leaves
— opposed to deciduous ; compare half-evergreen
b. : continuing without change in function or structure — used chiefly of animal structures that are characteristic of some ancestral type or of a larval or young stage
persistent gills
— opposed to deciduous
c. of a chemical warfare agent : effective in the open for an appreciable time (as at least 2 to 10 minutes) : volatilizing relatively slowly
mustard gas is a persistent gas
• per·sist·ent·ly adverb
II. adjective
1. : degraded only slowly by the environment
persistent pesticides
2. : remaining infective for a relatively long time in a vector after an initial period of incubation
persistent viruses