/euh mig"deuh loyd'/ , n. Petrol.
1. a volcanic rock in which rounded cavities formed by the expansion of gas or steam have later become filled with deposits of various minerals.
adj. Also, amygdaloidal .
2. (of rocks) containing amygdules.
4. Anat. of or pertaining to an amygdala.
[ 1785-95; amygdal ( a ) ALMOND + -OID ]