What is the meaning of the word "low-level"?

Definitions:

  1. at a low level in rank or importance copy to clipboard adjective
    • a lowlevel job copy to clipboard
  2. not intense copy to clipboard adjective
    • lowlevel radiation copy to clipboard
  3. occurring at a relatively low altitude copy to clipboard adjective
    • a lowlevel strafing run copy to clipboard

Synonyms: