Collimate is a term used to describe the process of aligning light rays or other forms of radiation into a parallel beam. Its antonym would be to disperse, which means to spread or scatter in different directions. Other antonyms for collimate could be to diverge, unfocus, disorganize, or misalign. These words are all opposite in meaning to the concept of collimation, which is a crucial process in many fields, including astronomy, microscopy, and radiology. In these fields, a well-collimated beam of light or radiation is necessary for accurate measurements, observations, and diagnoses.