lay low

verb3

1. •
   To topple or overcome; to cause to fall; (of a person) to knock out.

   • He was laid low by a vicious blow to the head.
2. •
   To put in an abject condition.

   • My lover had remained in New York with her family because she had picked up the plague, or something just as bad, that had laid her quite low. — 1979
3. •
   (informal, nonstandard) To lie low, to be inconspicuous, especially when the potential object of search.

   • We lay low until the shell went over and then would straighten up again. — 1904