substanial

Substanial is generally considered a misspelling of substantial. It does not have a separate entry in standard English dictionaries and is not recognized as a distinct term in formal usage. When encountered, it is typically the result of a typographical error, though in rare cases it may appear as a proper noun or brand name.

Substantial, the standard form, has several related senses. As an adjective it means large in size, amount, or importance; tangible or material in form rather than abstract; and meaningfully important or significant. In legal or scholarly contexts it can describe evidence or changes that are real and enduring rather than trivial. Substantial can also describe robust or well-built physical construction, as in substantial architecture, and can refer to a considerable but not necessarily precise quantity, as in a substantial sum of money.

Etymology traces substantial to Latin substantālis, from substantia meaning substance, essence, or support. It entered English via Old French and has carried senses related to substance, reality, and importance since the Middle English period.

Usage notes: in formal writing, use substantial (not substanial). Be mindful of near-synonyms such as considerable, significant, or tangible, selecting the term that best matches the intended nuance. If you encounter "substanial" in text, correct it to "substantial" unless it is clearly serving as a proper noun.