stratus

/ˈstɹeɪtəs/

IPA: /S T R AE1 T AH0 S/

noun
  1. 1

    A principal, low-level cloud type in the form of a gray layer with a rather uniform base, usually not associated with precipitation, and capable of producing corona phenomena and a weak, uniform luminance; abbreviated St.

Source: https://en.wiktionary.org/wiki/stratus