astragal vs astragalus

astragal and astragalus both are nouns.

Word	Noun	Adjective	Verb	Adverb
astragal	Yes	No	No	No
astragalus	Yes	No	No	No

As nouns, astragal and astragalus are synonyms defined as:

astragal and astragalus: the bone in the ankle that articulates with the leg bones to form the ankle joint

Other synonyms of astragal include anklebone, talus.

astragal (noun)	astragalus (noun)
a beaded molding for edging or decorating furniture	the bone in the ankle that articulates with the leg bones to form the ankle joint
the bone in the ankle that articulates with the leg bones to form the ankle joint