in bed vs laid up

in bed

prep
  • In terms of sexual prowess. 

  • While on a bed. 

laid up

adj
  • Unable to move about normally due to illness or injury, especially when confined to bed. 

  • Stored at a dock or other place of safety. 

How often have the words in bed and laid up occurred in a corpus of books? (source: Google Ngram Viewer )