Fun, jest, sport, game, play are comparable when they denote something (as an activity, an utterance, or a form of expression) that provides diversion or amusement or is intended to arouse laughter.
Fun implies amusement or an engagement in what interests as an end in itself, or it may apply to what provides this amusement or interest and then often additionally implies a propensity for laughing or for finding a usually genial cause for laughter or amusement.
Jest (see also JOKE ) is comparable to fun chiefly in fixed phrases (as in jest ) or when applied to activity or utterance not to be taken seriously. In such uses, however, jest commonly carries a stronger implication of ridicule or hoaxing.
Sport (see also PLAY 1 ) is often interchangeable with fun or jest. But its most common use is in certain idiomatic phrases (as make sport and in sport ) in which it suggests an intent to induce amusement or provoke laughter by putting someone or something up to gentle or malicious ridicule.
Game as a close synonym of fun survives chiefly in the phrase to make game of where, like sport in the corresponding idiom, it usually carries a suggestion of mischief or malice and implies a certain ridicule. In more general related use game (see also games under ATHLETICS ) may apply to an activity carried on in a spirit of fun.
Play, which stresses in all senses an opposition to earnest , may replace fun or sport or jest when a thoroughly innocuous implication of lack of earnestness or seriousness is desired.