| slab | 1. A thin piece of anything, especially of marble or other stone, having plane surfaces. 2. An outside piece taken from a log or timber in sawing it into boards, planks, etc. 3. <zoology> The wry neck. 4. The slack part of a sail. Slab line, a line or small rope by which seamen haul up the foot of the mainsail or foresail. Origin: OE. Slabbe, of uncertain origin; perhaps originally meaning, a smooth piece, and akin to slape, Icel. Sleipr slippery, and E. Slip, v. I. Source: Websters Dictionary (01 Mar 1998) |
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| slab-off | A process by which prism base-up is produced in the reading field of a spectacle lens through bicentric grinding. (05 Mar 2000) |
| slab-off lens | A spectacle lens with a base-up prism below; used in unequal myopia to equalise image displacement when reading. (05 Mar 2000) |