Adverb

1. In close proximity; crammed uncomfortably close together.

   All sorts of people lived cheek by jowl in the old city.

Usage notes

• The similar idiom implies a cozy, romantic situation, while cheek by jowl implies rather the opposite, being cramped or crowded.

Quotations

• Poultry farmers counter that the last avian flu to cross species (the Spanish flu out-break of 1918) did so in an era where factory farms didn't exist and poultry lived cheek-by-jowl with people. - The turkey trade, The Week, Issue 601, page 13.