rag
noun /ræɡ/
  /ræɡ/
 Idioms - [countable, uncountable] a piece of old, often torn, cloth used especially for cleaning things- I wiped the window with a damp rag.
- Use a piece of old rag.
 Extra ExamplesTopics Clothes and Fashionc1- He wiped his hands on an oily rag.
- The gun was wrapped in a dirty rag.
- You can wipe the stains off with a rag.
 Oxford Collocations Dictionaryadjective- clean
- dirty
- filthy
- …
 - bundle
- heap
- pile
- …
 - be dressed in
- wear
- be wrapped in
- …
 - on a/the rag
- with a rag
 
- [countable] (informal, usually disapproving) a newspaper that you believe to be of low quality- the local rag
- I don't know how you can bear to read that awful rag!
 
- [countable] a piece of ragtime music
- [uncountable, countable] (British English) an event or a series of events organized by students each year to raise money for charity- rag week
 
Word Originnoun senses 1 to 2 Middle English: probably a back-formation from ragged or raggy ‘ragged’. noun sense 4 mid 18th cent.: of unknown origin. noun sense 3 late 19th cent.: perhaps from ragged; compare with ragtime.
Idioms 
in rags 
- wearing very old torn clothes- The children were dressed in rags.
- I saw people dressed in rags begging on the street.
 
lose your rag 
- (British English, informal) to get angryTopics Feelingsc2
(from) rags to riches 
- from being extremely poor to being very rich- a rags-to-riches story
- Hers was a classic tale of rags to riches.
 
a red rag to a bull (British English) 
(US English like waving a red flag in front of a bull)
- something that is likely to make somebody very angry