\A*myg"da*loid\, n. [Gr. ? almond + -oid: cf. F.
amygdalo["i]de.] (Min.)
A variety of trap or basaltic rock, containing small
cavities, occupied, wholly or in part, by nodules or geodes
of different minerals, esp. agates, quartz, calcite, and the
zeolites. When the imbedded minerals are detached or removed
by decomposition, it is porous, like lava.

\A*myg"da*loid\, Amygdaloidal \A*myg`da*loid"al\, a.
1. Almond-shaped.
2. Pertaining to, or having the nature of, the rock
   amygdaloid.