Compulsive means driven by an urge that cannot be resisted. A person who lies or gambles without being able to help it.
The clinical sense is precise, and compulsive behaviour is a recognised feature of several conditions, most familiarly in obsessive-compulsive disorder. Everyday use is looser and describes a habit somebody cannot stop, so a compulsive liar lies without needing a reason. There is a third and entirely positive sense about things rather than people, since compulsive viewing or a compulsive read is something you cannot put down.
1adjectivecompulsiveDriven by an urge that is very hard to resist.
“He was a compulsive gambler by the age of thirty.”
2adjectiveabsorbingSo absorbing that you cannot stop.
“The series was utterly compulsive viewing.”
Compulsion is being driven. Latin compellere joins com, together, to pellere, to drive, so a compulsion pushes you along rather than persuading you.
Latin
compulsus
French
compulsif
English, today
compulsive
Built from
Borrowed from French compulsif, formed from Latin compulsus, past participle of compellere (“to compel”), from com- (“together”) + pellere (“to drive”).
Etymology from Wiktionary, CC BY-SA