third-rate

/TH ER1 D R EY0 T/
noun
  1. 1

    A British ship-of-the-line with 64 to 80 guns divided across two gun decks.

adjective
  1. 1

    Of lesser value or quality than second-rate.

  2. 2

    Describing a British ship-of-the-line with 64 to 80 guns divided across two gun decks.

Source: https://en.wiktionary.org/wiki/third-rate