--> I'll be there in a few minutes. I'm just finishing up a few odds and ends.
--> He has a few odds and ends yet to complete on his research project.
Of course
naturally; in the expected order of things.
--> Of course I loaned her the money---she's my sister.
--> Where were you last night? At home, of course.
Off and on or On and off
occasionally; erratically.
--> It rained off and on all day long.
--> Off and on throughout the day I received phone calls inquiring about my car which is for sale.
Off the beaten track
in an unfamiliar place; on a route that is not often traveled.
--> His home is in a quiet part of town, way off the beaten track.
--> Don't wander off the beaten track.
Off the top of one's head
to say something rapidly without having time to think or remember. (Informal)
--> I can't think of the answer off the top of my head.
--> Jane can tell you all the information right off the top of her head.
Off the wall
odd; silly; unusual. (Slang)
--> Why are you so off the wall today?
--> This book is strange. It is really off the wall.
Off to one side
beside something; moved slightly away from something.
--> Off to one side of the rose garden, there was a large pine tree.
--> He took me off to one side to tell me the bad news.
Old hand at doing (something)
someone who is experienced at doing something.
--> I'm an old hand at fixing clocks.
--> He is an old hand at changing babies' diapers.
On a diet
trying to lose weight by eating less food or specific foods.
--> I can't eat the cake. I'm on a diet.
--> I'm gaining weight. Next week I'll go on a diet.
On a roll
things are going smoothly and efficiently; things are being accomplished.
--> Please don't bother me, right now I am on a roll.
--> For days I only wrote a few sentences, but now I'm on a roll. The ideas are really flowing.
--> I'm on a roll.
On account of (someone or something)
because of someone or something.
--> We can't go out for a walk on account of the rain.
--> I was late for work on account of the traffic jam.
On cloud nine
very happy. (Informal)
--> When I got my first salary raise, I was on cloud nine.
--> He asked me to marry him. I'm on cloud nine.
On earth
how amazing. (Used as an intensifier after interrogative pronouns: Who, what, when, where, how.)
--> What on earth do you mean?
--> When on earth do you expect me to do that?
Similar: In creation and In the world.
--> How in creation do you expect me to do that?
On hand
available; nearby.
--> I always keep an extra fifty dollars on hand in case of emergency.
--> Don't worry. He is always on hand to help.
On one's feet
standing up.
--> Get on your feet.
--> I've been on my feet all day and they really hurt.
On one's feet
well and healthy, especially after an illness.
--> I hope to be back on my feet next week.
--> I can help you as soon as I'm back on my feet.
On one's mind
occupying one's thoughts; currently being thought about.
--> You've been on my mind all day.
--> You look upset. What's on your mind?
--> I have a lot on my mind these days.
On one's own
by oneself.
--> Did you do this on your own, or did someone help you?
--> My son is married and on his own now.
--> Very few people learn English on their own.
On purpose
for a reason; intentionally.
--> He did this on purpose. It was no accident.
--> The child spilled the soup on purpose so that he would not have to eat it.
On sale
offered for sale at a special low price.
--> I always wait until clothes are on sale before I buy anything.
--> Is this radio on sale?
--> I won't buy anything that isn't on sale.
