| frog [fräg] DESIGN ENGINEERING A hollow on one or both of the larger faces of a brick or block; reduces weight of the brick or block; may be filled with mortar. Also known as panel. ENGINEERING A device which permits the train or tram wheels on one rail of a track to cross the rail of an intersecting track. VERTEBRATE ZOOLOGY The common name for a number of tailless amphibians in the order Anura; most have hindlegs adapted for jumping, scaleless skin, and large eyes. |