| Webster's Online Dictionary |
| Part of Speech | Definition | |
| Expression | 1. A heavy optical glass, consisting essentially of a borosilicate of potash.[Websters]. | |
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| Expressions | Definition | ||
| Heavy glass | A heavy optical glass, consisting essentially of a borosilicate of potash. Source: Webster's Revised Unabridged Dictionary. | ||
Source: compiled by the editor from various references; see credits. | Top | ||