lay down

verb11

1. •
   To place or install on the ground, e.g. a railway on a trackbed.

   • Two standard types of flat-bottom track were introduced as early as 1949, and some 1,570 miles had been laid down to the end of 1950. — 1951
2. •
   To specify, institute, enact, assert firmly, state authoritatively, establish or formulate (rules or policies).

   • Let's lay down the rules right at the beginning, so we are consistent.
   • You've got to lay down the law with that boy.
3. •
   To give up, surrender, or yield (e.g. a weapon), usually by placing it on the ground.

   • The police urged the gunman to lay down his weapon.
   • Lay down your arms.
4. •
   To sacrifice, especially in the phrase "to lay down one's life."
5. •
   (nonstandard) To lie down.

   • I feel a bit ill, so I'm going to go lay down for a while.
6. •
   To stock, store (e.g. wine) for the future. See also lay by.
7. •
   To intentionally take a fall while riding a motorcycle, in order to prevent a more serious collision.

   • He laid down his brand-new Harley-Davidson to avoid the oncoming bus.
8. •
   (old-fashioned) To kill (someone).
9. •
   (euphemistic) To euthanize an animal.
10. •
    (old-fashioned) To draw the lines of a ship's hull at full size, before starting a build.
11. •
    (no longer used) To place a sheet in a printing press for printing.