gridiron
n. US //ˈɡɹɪˌdaɪɝn// UK //ɡɹˈɪdaɪən// grid·iron
From Middle English gridirne, gredirne, gredyron, gredeyron, grydern, grydyryne, girdirin, girderen, variants of Middle English gredire, gredyre, itself an alteration of Middle English gridel (“griddle”). The ending was assimilated to iron, as if from grid + iron, whence grid was later derived.
From resembling the shape of a gridiron (a square rectilinear grid).