Learner's definition of CONSTRAINT
something that limits or restricts someone or something
— usually plural
Budget constraints [=restrictions] have forced me to revise my travel plans. [=I've changed my travel plans because I do not have enough money]
Because of time constraints [=limitations], speeches will be limited to five minutes.
Tradition puts/places/imposes constraints on [=puts limits on] people and their actions.
control that limits or restricts someone's actions or behavior