1: : to come to the consistency of jelly : congeal, set 2: to take shape and achieve distinctness : become cohesive
Not to be confused with the verb gel, which means... to become a gel, which is what jelly is anyhow. So, actually, feel free to confuse gel with jell. I'm confused now. Stupid English.
Both jell and gel are nice little five cent words, short and sweet.
More specific than:
Form, set and most other synonyms. Because of my scientific background, I think of jell specifically in terms of the internal structure that makes gels what they are -- a web of molecules, like a three-dimensional fishing net. It's the creation of an orderly array, so the use of jell in unstructured situations won't ring true for me.
IMO, the closest synonym to jell is clot, because clots are also a self-arranged structure. They're just not orderly, like gels. Clots can congeal or coalesce, both of which might involve internal structure, but not necessarily. Cohere is tricky because I tend to think it requires stickiness... but I'm sure that physicists would say that coherent light (a laser) has rigorous internal structure like a gel.
Set and form are both vague and apply to a number of things, like concrete, which have no internal structure.
What comes to your mind?