[bahy-prod-uh
kt] 
| 1. | a secondary or incidental product, as in a process of manufacture. |
| 2. | the result of another action, often unforeseen or unintended. |
| by-product (bī'prŏd'əkt) Pronunciation Key
Something produced in the process of making something else. When plants produce carbohydrates by photosynthesis, oxygen is released as a by-product. Asphalt and paraffin are by-products of the process of refining crude oil into gasoline. |