cheek by jowl

Short definition from Wiktionary

Adverb

1. 1
   In very close physical proximity, crowded together.
2. 2
   In very close or intimate association.
3. 3
   Alternative form of cheek by jowl.

Adjective

1. 1
   Tightly packed.
2. 2
   Alternative form of cheek by jowl.