Bad

Bad is an adjective used in English to describe something that is of low quality, harmful, undesirable, or morally wrong. It can apply to objects, actions, situations, or people, and its precise meaning depends on context. Examples include bad weather, a bad decision, bad behavior, or a bad taste. In moral philosophy, badness concerns harm, vice, or violation of standards of conduct; in aesthetics, it denotes unattractive or displeasing qualities; in health or safety, it signals danger or risk. While good and bad form a basic evaluative pair, judgments of badness are often subjective and culturally conditioned.

Grammar and usage: The standard comparative form is worse and the superlative worst. As an adverb, badly is preferred in formal usage, though informal speech sometimes uses bad as an adverb (e.g., ‘he plays badly’ vs ‘he plays bad’). In some dialects, bad can function as an intensifier meaning especially strong or impressive, especially in colloquial speech.

Etymology and related terms: The word has ancient Germanic roots and has cognates in related languages; its sense of moral or practical deficiency has persisted across history.

In culture: In popular culture, Bad is the title of Michael Jackson's 1987 album and its hit single "Bad," which achieved international commercial success.