'Gridiron valve' definitions:

Definition of 'Gridiron valve'

From: GCIDE

Gridiron \Grid"i`ron\, n. [OE. gredire, gredirne, from the same source as E. griddle, but the ending was confused with E. iron. See Griddle.]
1. A grated iron utensil for broiling flesh and fish over coals. [1913 Webster]
2. (Naut.) An openwork frame on which vessels are placed for examination, cleaning, and repairs.
3. (Sport) A football field; -- so called because of the resemblance of the parallel marked yard lines to a gridiron[1]. [PJC]
Gridiron pendulum. See under Pendulum.
Gridiron valve (Steam Engine), a slide valve with several parallel perforations corresponding to openings in the seat on which the valve moves. [1913 Webster]