Definition

/ɔːf/

noun

(usually in phrases such as 'from the off', 'at the off', etc.) Beginning; starting point.
“He has been very obviously an untrustworthy narrator right from the off.”

verb

adjective

Inoperative, disabled.
“All the lights are off.”
Cancelled; not happening.
“The party's off because the hostess is sick.”
Not fitted; not being worn.
“The drink spilled out of the bottle because the top was off.”
Rancid, rotten, gone bad.
“This milk is off!”
Less than normal, in temperament or in result.
“sales are off this quarter”

adverb

In a direction away from the speaker or object.
“He drove off in a cloud of smoke.”
Into a state of non-operation or non-existence.
“Please switch off the light when you leave.”
So as to remove or separate, or be removed or separated.
“He bit off the end of the carrot.”
Used in various other ways specific to individual idiomatic phrases, e.g. bring off, show off, put off, tell off, etc. See the entry for the individual phrase.

preposition

Not positioned upon; away from a position upon.
“He's off the roof now.”
Detached, separated, excluded or disconnected from; away from a position of attachment or connection to.
“He was thrown off the team for cheating.”
Used to indicate the location or direction of one thing relative to another, implying adjacency or accessibility via.
“His office is off this corridor on the right.”
Used to express location at sea relative to land or mainland.
“The island is 23 miles off the cape.”
Removed or subtracted from.
“There's 20% off the list price.”