| Webster's Online Dictionary |
| Part of Speech | Definition | |
| Expression | 1. The distance of the image of an object from the object glass.[Websters]. | |
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| Expressions | Definition | ||
| Focal distance of a telescope | The distance of the image of an object from the object glass. Source: Webster's Revised Unabridged Dictionary. | ||
Source: compiled by the editor from various references; see credits. | Top | ||