1 used for connecting possibilities or choices. In a list, ‘or’ is usually used only before the last possibility or choice
Which colour do you want – red, green, yellow, or blue?
He’s probably at lunch or in a meeting.
either... or: ‘When will you get the results?’ ‘Either tomorrow or the day after.’
whether... or: You don’t care whether he lives or dies, do you?
or not: The jury must decide whether the prisoner is guilty or not.
Synonyms and related words