noun, plural M-1's.
Definition for m1 (2 of 2)
Examples from the Web for m1
In several specimens, however, the re-entrant fold is absent from the lingual surface of M1.North American Jumping Mice (Genus Zapus)|Philip H. Krutzsch
Of these parts, right m2, left coronoid process, right P4 and M1 and adjacent part of maxilla are lost.American Weasels|E. Raymond Hall
At this stage, the occlusal configuration would be in a U-pattern (m1 in Fig. 5E).
M1 and M2, like the lower molars, are elliptical in cross-section.
In addition there is a rostrum that on the right side bears the last two unicuspids, P4, M1, and M2.Pleistocene Soricidae from San Josecito Cave, Nuevo Leon, Mexico|James S. Findley
British Dictionary definitions for m1 (1 of 4)
British Dictionary definitions for m1 (2 of 4)
noun plural m's, M's or Ms
British Dictionary definitions for m1 (3 of 4)
British Dictionary definitions for m1 (4 of 4)
- mature audience (used to describe a category of film certified as suitable for viewing by anyone over the age of 15)
- (as modifier)an M film
Word Origin and History for m1
13th letter, from Greek mu, from Semitic mem. The Roman symbol for 1,000; sometimes used in this sense in English 15c.-16c.; but in late 20c. newspaper headlines it stands for million. As a thickness of type, from 1680s.