verb (used without object)
to take charge of a child while the parents are temporarily away.
verb (used with object)
to baby-sit for (a child): We've placed an ad for someone to baby-sit the youngsters in the evening.
to take watchful responsibility for; tend: It will be necessary for someone to baby-sit the machine until it is running properly.
Origin: Related forms
baby-sitter, babysitter, noun