These words all refer to people or things that are aesthetically displeasing or objectionable. Ugly is the strongest and most unfavourable word and is broadest in application. It may refer to morally repulsive behaviour as well as to people or things that are distasteful in appearance: an ugly hat; an ugly tenement building; in an ugly mood. Because of the blunt force of ugly when applied to people, homely , plain or unattractive , which have softer or more diffuse impacts, are often preferred in describing someone of unpleasing appearance.

Homely , influenced by its basic sense meaning familiar or everyday in character, is an Americanism which implies ugliness by reason of a common, dull or gross appearance entirely lacking in any appealing or distinguishing feature. This use sometimes applies in Australia and New Zealand, but the word usually has milder connotations of lacking beauty or needing polish and refinement: a simple, homely type of girl. Plain also emphasizes a lack of distinction that would lend interest or appeal.

• The older sister was unfortunately rather homely and was never married; The girl, though plain , had a good, kind face.

Unattractive is more diffuse and vaguer than plain or homely , and may be applied to things and behaviour as well as to personal appearance: an unattractive habit of cracking his knuckles; a pimply, unattractive child; an unattractive neighbourhood, with run-down rooming houses and dingy shops. A person or thing considered unattractive is not necessarily ugly. Whereas ugly usually implies inherent form or nature, unattractive may refer to a superficial or temporary aspect or condition: an unattractive window display; He considered Byzantine architecture ugly .

Homely and plain usually apply specifically to facial appearance, and since women are commonly judged on the basis of personal beauty, these terms, as well as unattractive , are more often applied to women than men. Indeed, when a man is far from handsome no one hesitates to call him ugly , because the word’s force seems masculine in strength, and few men have such a great stake in their looks that they would regard ugly as shocking or excessive, especially when the word is applied to someone else. But to call a woman ugly is like calling a man pretty; it can hardly be taken as other than a deliberate insult.

Unsightly means offensive to the sight, and is most often used to describe an aspect rather than a person: Johnson made an unsightly appearance in his tiny, ill-fitting wig and loose black breeches; shampoos designed to rid one of unsightly dandruff. Unsightly suggests more elegant standards than the other words discussed here; it has a prim quality that implies a failure to measure up to some standard of visual decency, decorum or propriety. It does not indicate ugliness as such, but rather the visual pain of observing a breach of taste or manners: an unsightly stain on his tie.