| synthesis gas | |
| —n | |
| 1. | a mixture of carbon dioxide, carbon monoxide, and hydrogen formerly made by using water gas and reacting it with steam to enrich the proportion of hydrogen for use in the synthesis of ammonia |
| 2. | a similar mixture of gases made by steam reforming natural gas, used for synthesizing organic chemicals and as a fuel |
| a screen or mat covered with a dark material for shielding a camera lens from excess light or glare. |
| a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question. |