Substantial

google

ref

Middle English: from Old French substantiel or Christian Latin substantialis, from substantia ‘being, essence’ (see substance).

wiktionary

ref

From Old French substantiel.

etymonline

ref

substantial (adj.)

mid-14c., "ample, sizeable," from Old French substantiel (13c.) and directly from Latin substantialis "having substance or reality, material," in Late Latin "pertaining to the substance or essence," from substantia "being, essence, material" (see substance). Meaning "existing, having real existence" is from late 14c. Meaning "involving an essential part or point" is early 15c. Related: Substantially.