From The Collaborative International Dictionary of English v.0.48 :
CRO \CRO\ n. (Electronics)
acronym for cathode-ray oscilloscope, an electronic device
which provides visual images of varying electrical
quantities. See oscilloscope.
Syn: oscilloscope, scope, cathode-ray oscilloscope.
[WordNet 1.5]
From WordNet (r) 3.0 (2006) :
CRO
n 1: electronic equipment that provides visual images of varying
electrical quantities [syn: oscilloscope, scope,
cathode-ray oscilloscope, CRO]