The Collaborative International Dictionary of English v.0.48:

Lamina \Lam"i*na\ (l[a^]m"[i^]*n[.a]), n.; pl. L. Lamin[ae]
   (-n[=e]) E. Laminas (-n[.a]z). [L. cf. Lamella.]
   1. A thin plate or scale; a layer or coat lying over another;
      -- said of thin plates or platelike substances, as of bone
      or minerals.
      [1913 Webster]

   2. (Bot.) The blade of a leaf; the broad, expanded portion of
      a petal or sepal of a flower. --Gray.
      [1913 Webster]

   3. (Zool.) A thin plate or scale; specif., one of the thin,
      flat processes composing the vane of a feather.
      [1913 Webster]