noun
Usage: usually capitalized 3d M
Etymology: mark (I)
1.
a. : a Freemason of the fourth degree in the order in the United States
b. : a Freemason of the first degree of Royal Arch Masonry in the United States
2.
a. : a Freemason of a distinct lodge associated with the Grand Lodge of mark Masons in England
b. : a degree conferred under the authority of the Grand Chapter in Scotland