CLC

CLC is a FAA Acronym for: Course Line Computer
Related Definitions from Aviation Glossary
GSA
GHA
Military Operations Area (MOA)
ATA - Air Transport Association
MRO ...

RNAV is a system that uses a VOR/DME or a VORTAC (VOR and Military TACAN) in combination with a course line computer (CLC).

a. VORTAC referenced or Course Line Computer (CLC) systems, which account for the greatest number of RNAV units in use. To function, the CLC must be within the service range of a VORTAC.