| A | B |
| Contagious | Pertaining to an emotion, feeling, or attitude that spreads to and affect others. |
| Giggle | To laugh lightly and repeatedly in a silly way, from amusement, nervousness, or embarrassment. |
| Tickle | To lightly touch or prod, a person or a part of the body in a way that causes mild discomfort or itching and often laughter. |
| Amuse | A cause or reason to be funny. |
| Species | A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. |
| Endorphins | A chemical naturally, released in the brain to reduce pain, that in large amounts can make you feel relaxed or full of energy. |
| Evolve | To develop gradually. |
| Bond | A relationship between people or groups based on shared feelings, interests, or experiences. |
| Trigger | To cause a strong emotional reaction that can be either good or bad. |
| To Crack Up | An joyful reaction to a situation that causes laughter to occur. |