D defs.my
Entry 1 sense Webster, 1913

Spad

/(spăd)/ · IPA /ˈspæd/
01 n. A nail one or two inches long, of iron, brass, tin, or tinner iron, with a hole through the flattened head, used to mark stations in underg…
  1. 1.
    A nail one or two inches long, of iron, brass, tin, or tinner iron, with a hole through the flattened head, used to mark stations in underground surveying.(Mining)