Ca
| n. | 1. | the chemical symbol for calcium, the fifth most abundant element in the earth's crust. |
| Noun | 1. |  Ca - a white metallic element that burns with a brilliant light; the fifth most abundant element in the earth's crust; an important component of most plants and animalsSynonyms: atomic number 20, calcium |
| 2. |  CA - a state in the western United States on the Pacific; the 3rd largest state; known for earthquakes |
| 1. | (theory, architecture) | CA - cellular automaton. | |
| 2. | (company) | CA - Computer Associates. | |
| 3. | (cryptography) | CA - Certificate Authority. | |
| 4. | (networking) | ca - The country code for Canada. |