sardinewise

sardine +‎ -wise, from the way that those fish are tinned.

sardinewise (not comparable)

1. Packed tightly into a small space.
   • 1894, George Du Maurier, Trilby‎, New York: Harper, Part 5, p. 250:

     And what added so much to the charm of this delightful concert was that the guests were not packed together sardinewise, as they are at most concerts; they were comparatively few and well chosen, and could get up and walk about and talk to their friends between the pieces […]

   • 1967, Edmund Wilson, A Prelude‎, New York: Farrar, Straus and Giroux, page 181:

     David Hamilton offered to share his bunk with me, and we slept head to feet, sardinewise.

• packed like sardines
• sardinelike