| A | B |
| Algorithm | a set of rules for solving a problem in a finite number of steps, as for finding the greatest common divisor |
| Asymptote | a straight line approached by a given curve as one of the variables in the equation of the curve approaches infinity. |
| Collide | A mutual act which can occur only when both objects are moving |
| Communicate | The mutual act of acknowledging or interacting with another person |
| Complement | To highlight, set off, or perfect, (n) something that completes or makes better |
| Compliment | Praise or Flattery |
| Compose | to make or form by combining things, parts, or elements |
| Comprise | To be made up of |
| Compunction | A feeling of shame or regret for one's actions or words |
| Convivial | riendly; agreeable |
| Double-entendre | A word or phrase having a double meaning |
| Ecology | the branch of biology dealing with the relations and interactions between organisms and their environment, including other organisms |