\vee
Logical disjunction or 'or' operator, often used in logic and set theory to denote the union of two sets or the logical 'or' between two statements.
Logical 'or' between statements A and B
A \vee B
Logical 'or' between predicates P and Q
P(x) \vee Q(x)
Logical 'or' condition for x being greater than 0 or less than -1
(x > 0) \vee (x < -1)