CRT may refer to: In education: Criterion-referenced test, a type of exam a Substitute teacher (or casual relief teacher) In electronics and computing: Cathode ray tube, a type of large display (or monitor) The C runtime library (part of the C standard library), in programming In law: Charitable remainder trust Contractors Response Time, in service level agreements In medicine: Capillary refill time, a medical sign Corneal Refractive Therapy, in optometrics Cognitive Retention Therap… (More on Crt)