Dictionary:

adv.
From a place or position: drove off.
At a certain distance in space or time: a mile off; a week off.
From a given course or route; aside: swerved off into a ditch.
Into a state of unconsciousness: I must have dozed off.
So as to be no longer on, attached, or connected: shaved off his mustache.
So as to be divided: marked off the playing field by yards.
So as to be no longer continuing, operating, or functioning: switched off the radio.
So as to be completely removed, finished, or eliminated: kill off the mice.
So as to be smaller, fewer, or less: Sales dropped off.
So as to be away from work or duty: They took a day off.
Offstage.adj.
Distant or removed; farther: the off side of the barn.
Remote; slim: stopped by on the off chance that they're home.
Not on, attached, or connected: with my shoes off.
Not operating or operational: The oven is off.
No longer taking place; canceled: The wedding is off.
Slack: Production was off this year.
Not up to standard; below a normal or satisfactory level: Your pitching is off today.
Not accurate; incorrect: Your statistical results are off.
Somewhat crazy; eccentric: I think that person is a little off.
Started on the way; going: I'm off to see the president.
Absent or away from work or duty: She's off every Tuesday.
Spent away from work or duty: My off day is Saturday.
Being on the right side of an animal or vehicle.
Being the animal or vehicle on the right.
Nautical. Farthest from the shore; seaward.
Sports. Toward or designating the side of the field facing the batsman in cricket.
Off-color.prep.
So as to be removed or distant from: The bird hopped off the branch.
Away or relieved from: off duty.
By consuming: living off locusts and honey.
With the means provided by: living off my pension.
Informal. From: “What else do you want off me?” (Jimmy Breslin).
Extending or branching out from: an artery off the heart.
Not up to the usual standard of: off his game.
So as to abstain from: went off narcotics.
Nautical. To seaward of: a mile off Sandy Hook.v., offed, off·ing, offs.
v.intr.
To go away; leave: Off or I'll call the police.v.tr. Slang.
To murder.idiom:
off and on
In an intermittent manner: slept off and on last night.
[Variant of Middle English of, from Old English.]
USAGE NOTE The compound preposition off of is generally regarded as informal and is best avoided in formal speech and writing: He stepped off (not off of) the platform. Off is informal as well when used to indicate a source: formal style requires I borrowed it from (not off) my brother.