fourth-rate

Short definition from Wiktionary

Adjective

1. 1
   Of a Royal Navy ship of the line in the Napoleonic Era: having 50–60 guns across two gun decks, a complement of 320–420, and weighing approximately 1,000 tons burthen.
2. 2
   Terrible, awful; less than third-rate.
3. 3
   Alternative spelling of fourth-rate.

Noun

1. 1
   A fourth-rate ship of the line.
2. 2
   Alternative spelling of fourth-rate.