non-trivial
This is used to describe something that most people would just call “hard.” However cs people need to make sure to tell you that it’s actually “not extremely easy.” You will probably find a cs person using non-trivial where it should not be used. For example, “Doing the laundry is completely non-trivial.”

well-defined
ambiguous
These two go together. Well-defined and ambiguos usually refer to descriptions of problems, but cs people can really use them for anything. “I’m not sure if my wants and needs are well-defined.” “The solution to your girl problems is ambiguos.”

What other words do cs people use too much?