Of mediocre quality; not first-rate.
Of a Royal Navy ship of the line in the Napoleonic Era: having 80–98 guns across three gun decks, a complement of 700–750, and weighing approximately 2,200 tons burthen.
A second-rate ship of the line.
Of a rare quality, unusual.
Being the only one of its kind; unequaled, unparalleled or unmatched.
Of a feature, such that only one holder has it.
Particular, characteristic.
A thing without a like; something unequalled or unparallelled; one of a kind.