The Collaborative International Dictionary
buttonmould
Buttonmold \But"ton*mold`\, n. A disk of bone, wood, or other material, which is made into a button by covering it with cloth. [Written also buttonmould.]
Fossil buttonmolds, joints of encrinites. See Encrinite.
Wiktionary
buttonmould
n. (context archaic English) A disc of bone, wood, or other material, made into a button by covering it with cloth.