RAIN OFF (usually passive) Definition: to stop something happening because it is raining. E.g.1: We had planned to have a picnic yesterday, but it was rained off. We’ll have the picnic when the weather improves. E.g.2: A: Are you going to watch the cricket match today? B: No. It’s been rained off. They are going to play it next weekend, if it doesn’t rain! This phrasal verb cannot be separated.

RAKE OVER Definition: to continue to talk about an unpleasant event that happened in the past even though it would be better to forget it. (This phrasal verb has more than one meaning) E.g.1: Why rake over the troubles of the past? Let’s look to the future! E.g.2: Some people say it’s best to forget the past and not rake over painful memories. This phrasal verb can’t be separated.

READ UP ON Definition: to read everything you can about a subject so that you know it thoroughly. E.g.1: I'm going to the library to read up on genetic engineering E.g.2: He knows a lot about it, doesn't he? Yes, he spent the weekend reading up on it. This phrasal verb cannot be separated.

ROLL (something) UP (N.B. the opposite is ‘unroll’, not ‘roll down’) Definition: to wrap something, such as paper or cloth, around itself several times so that it looks like a cylinder. (This phrasal verb has more than one meaning) E.g.1: He rolled up his newspaper and used it to kill the spider which was crawling up the wall. E.g.2: If you roll the carpet up it will be easier to carry. This phrasal verb can be separated. (E.g. 2)

ROUND (something) UP Definition: to increase the size of a fraction to the nearest whole number, or to increase a number to the nearest 10, or the nearest 100 etc. E.g.1: The answer was 6.982, so I rounded it up to 7. E.g.2: To simplify the graph, the sales figures have been rounded up to the nearest 100. This phrasal verb can be separated. (E.g.1). (the opposite is: round (something) down) (This phrasal verb has more than one meaning) 

RUN OUT Definition: to have no more of something you usually have. (This phrasal verb has more than one meaning) E.g.1. Oh no! I’ve run out of cigarettes! E.g.2. Do we have any bread? No. We’ve run out.. This phrasal verb can’t be separated.

RUSTLE UP Definition: to cook a meal quickly using whatever ingredients are available at the time. E.g.1: There isn’t much food in the fridge, but I could rustle something up. What about an omelette? E.g.2: She’s a great cook. She can rustle up a delicious meal from almost anything. This phrasal verb can be separated.