- CR manifold
- CR-manifold
- C^r manifold
- Cr manifold
- Cr-manifold
- CR MOLY
- CRN
- cRNA
- CRO
- Croatia
- Croatian cross
- Croatian Museum of Naïve Art
- Croatian Peasants’ Uprising
- CRO=cathode-ray oscillograph oscilloscope
- Crocco crater
- Croce-Collinwood's theory of expression
- crochet
- crocheted fabric
- crocheting machine
- Crocker Art Museum
- crocodile dilemma
- Crocodile Dundee
- crocodile tears syndrome
- crocodilians
- crocoite