if i say a cat means an small animal with....... can i replace 'means' with 'refer' in this case?

Yes, you can replace "means" with "refer" in this case, but there are subtle differences in their usage.

When you say "a cat means a small animal with...", the term "means" establishes a direct definition or equivalence. It implies that the term "cat" is defined by the characteristics that follow.

On the other hand, saying "a cat refers to a small animal with..." indicates a broader sense of connection. It suggests that "cat" is one term used to describe that particular kind of animal, but it doesn't strictly imply a definition in the way "means" does.

In summary, both can be used, but "means" is more definitive, while "refer" is more descriptive and flexible. Choose based on the level of specificity you wish to convey in your statement.