• Definition: 

(1) to clean something by causing water to pass through it

• Collocation: flush sth out (with sth); flush sth out through sth

• Examples: Flush the pipe out with clean water; Drinking lots of water will help to flush toxins out of the body

(2) (of a person or their face) to become red, especially because you are embarrassed, angry or hot

• Collocation: flush + adj; flush sth

• Example: Sam felt her cheeks flush red; A rosy blush flushed her cheeks