Idea
In category theory, A weak (co)limit is the extension of the categorical definiton to (co)limit, still requiring all other (co)cones to factor into the limit, but lifting the uniqueness requirement.
Definition
Let be a category and be a diagram. Then a weak limit is a weak terminal object in the category of -cones. Dually, a weak colimit is a weakly-initial object of the category of -cocones.