Competent means having enough skill to do the job right. A competent electrician, a competent driver: nothing goes wrong, nothing catches fire, nobody has to be called back.
The catch is the temperature of the word. Call a performance competent and you have said it was fine and no more — competent is the faintest praise English hands out, a step above adequate and a long way below good. The noun is competence, and competency in job adverts and training courses. Law and administration use it flatly: a competent court, a competent authority, competent to stand trial, where it means having the legal power rather than being any good. You are competent AT a task and competent IN a language, and the pair is lopsided, because incompetent is a real insult.
1adjectivecompetentHaving the skill or knowledge to do something properly.
“She is a competent teacher with fifteen years behind her.”
synonyms: able, skilled, proficient
2adjectivegoodGood enough, and no better.
“The band gave a competent performance that nobody will remember.”
3adjectivepowerHaving the legal power or capacity to act or decide.
“The case must be heard by a competent court.”
Also accepted in games: capable
Latin competō meant to coincide, to be equal to, to be capable of — to match what is being asked. Its present participle competens came through Old French into Middle English as competent. A competent person is one who measures up, which is why the word still sounds like a pass mark rather than a prize.
Proto-Indo-European
*peth₂-
Latin
competens
Old French
competent
Middle English
competent
English, today
competent
Built from
From Middle English competent, conpetent, from Old French competent (modern French compétent), from Latin competens, present participle of competō (“coincide, be equal to, be capable of”). Compare Dutch competent (“competent”), German kompetent (“competent”), Danish kompetent (“competent”).
Etymology from Wiktionary, CC BY-SA