Substantially

Substantially is an adverb used to express that something is true to a large extent or in a major way, though not wholly. It comes from the adjective substantial, meaning having substance, size, or importance, and is formed with the standard -ly suffix. The word traces to Latin substantia, through Old French and Middle English.

Usage and nuance: In everyday language, substantially implies that most aspects are true or that a change is significant but not total. It allows for partial fulfillment or partial similarity. In legal and regulatory contexts, substantially can signal a standard that permits minor deviations while preserving core obligations or effects; phrases like substantially comply, substantially comply with regulations, substantially identical, or substantially all are common. The precise meaning depends on context and jurisdiction, and it can avoid the need to specify exact thresholds.

Examples: The plan substantially meets the safety requirements. The contract was substantially performed. The two methods are substantially identical.

See also: substantial, substantiality, substantially all, substantial difference.