| Term | Definition |
| tropos | turning |
| tropical | the climate of the earth in the tropics |
| phototropic | turning toward light as leaves and flowers do |
| heliotrope | a flower named for its tendency to turn toward the sun |
| tropophilous | plants or trees which like a change or turning of seasons-hot and cold, wet and dry |
| thermotropism | turning toward heat |
| philia | love, friendship |
| philosopher | one who loves wisdom |
| Philadelphia | city of brotherly love |
| philanthropist | one who cares about his fellow man |
| philologist | one who loves words |
| philtre | love potion |