lowest-grade

Adjective

low-grade (comparative lower-grade, superlative lowest-grade)

1. Of inferior quality.
   • Were the possibilities of improving the efficiency of British Railways' steam locomotives by making the best use of the reasonably satisfactory low-grade lump coal available today, and thereby saving more high-grade locomotive coal, borne in mind when it was decided to go ahead rapidly with...1961 September, “Talking of Trains: Greater scope for steam”, in Modern Railways, page 517

   Synonyms:

   lousy, low-rent, second-rate, ass, bad, base, below par, bottom-shelf, BTEC, bum

   Antonyms:

   high-grade

2. Minor.
   • These studies have identified a novel role for MLKL in aging, revealing a delay in the age-related reduction in circulating lymphocytes and a protection from chronic, low-grade, sterile inflammation in female Mlkl^(–/–) aged mice.2023 February 8, Emma C. Tovey Crutchfield; Sarah E. Garnish; Jessica Day; Holly Anderton; Shene Chiou; Anne Hempel; Cathrine Hall; Komal M. Patel; Pradnya Gangatirkar; Katherine R. Martin; Connie S....

   Antonyms:

   high-grade

3. Not steep; nearly level (having a low grade).