MAJ meaning in Medical ?

A majority, also called a simple majority to distinguish it from similar terms (see the "Related terms" section below), is the greater part, or more than half, of the total. It is a subset of a set consisting of more than half of the set's elements. For example, if a group consists of 20 individuals, a majority would be 11 or more individuals, while having 10 or fewer individuals would not constitute a majority. "Majority" can be used to specify the voting requirement, as in a "majority vote", which means more than half of the votes cast.

A majority can be compared to a plurality, which is a subset larger than any other subset but not necessarily larger than all other subsets combined. For example, if there is a group with 20 members which is divided into subgroups with 9, 6, and 5 members, then the 9-member group would be the plurality. A plurality is not necessarily a majority as the largest subset considered may consist of less than half the set's elements. This can occur when there are three or more possible choices.

In British English the term "majority" is also alternatively used to refer to the winning margin, i.e., the number of votes separating the first-place finisher from the second-place finisher. Other related terms containing the word "majority" have their own meanings, which may sometimes be inconsistent in usage.