a. [f. prec. + -AL 1.] Pertaining to, or of the nature or character of, the rock amygdaloid.
1813. Bakewell, Introd. Geol., 28. Amygdaloidal … when composed of a compact ground with cavities which have been filled up with another mineral substance.
1858. Geikie, Hist. Boulder, xii. 24. The same rocks may be likewise vesicular or amygdaloidal.
