Persistent means it will not stop and it will not go away. The cough that is still there in week three. A persistent leak under the sink, a persistent rumour about the head teacher, persistent rain that ruins a whole week of a holiday.
Used about people the word turns admiring or irritating depending on who is speaking: a persistent salesman who rings back six times, a persistent journalist who finally gets an answer. The noun is persistence and the verb is persist, as in he persisted in calling her by the wrong name. Scientists use it for chemicals that refuse to break down, the persistent pollutants that stay in soil for decades, and computing borrowed it for data that survives when the power goes off. Do not swap it with consistent, because consistent means always the same while persistent means it keeps going.
1adjectivecontinuousContinuing for a long time without stopping or easing.
“A persistent draught came from under the door all winter.”
synonyms: continuous, unrelenting, chronic
2adjectivepersistentOf a person: refusing to give up, even after being refused.
“He was persistent enough to get a real answer out of the council.”
3adjectivesubstanceOf a substance or of data: lasting instead of breaking down or being lost.
“These persistent chemicals are still turning up in river water.”
Persistent comes straight from Latin persistēns, the present participle of persistō, to continue steadfastly. Inside that verb sit per, meaning through, and the Proto-Indo-European root *steh₂-, the root of standing, which also holds up stand, stable, statue and station. A persistent cough is one that keeps standing there, right through everything you throw at it.
Proto-Indo-European
*steh₂-
Latin
persistēns
English, today
persistent
Built from
From Latin persistēns, present participle of persistō (“continue steadfastly”). by surface analysis, persist + -ent.
Etymology from Wiktionary, CC BY-SA