B2a thing or person that is used instead of another thing or person: Tofu can be used as a meat substitute in vegetarianrecipes.Vitamins should not be used as a substitute for a healthydiet.Replacing and exchanging›(informalsub)in sports, a player who is used for part of a gameinstead of another player: Johnson came on as a substitute towards the end of the match.The managerbrought on (US alsosent in) another substitute in the finalminutes of the game.Replacing and exchangingCompetitors and participants in sports and gamesthere is no substitute for sth›nothing is as good as the stated thing: You can work from plans of a garden, but there's no substitute for visiting the site yourself.Replacing and exchanging›(alsosubstitute teacher, informalsub)US forsupply teacherTeachers