adjective, verb, -grad⋅ed, -grad⋅ing.| 1. | of excellent or superior quality. |
| 2. | (of ore) yielding a relatively large amount of the metal for which it is mined. |
| 3. | to steal (rich ore) from a mine. |

| high-grade (hī'grād') adj. Of superior grade or quality. |
high-grade