selly /ˈsɛli/adjective 1adverb 1noun 1forms 5 adjective1 •(dialect, UK) Rare; wonderful; admirable adverb1 •(dialect, UK) Wonderfully, wondrously.His brother was […] selly sick and sore unsound. — 1889 noun1 •(dialect, UK) A marvel; wonder; something wonderful or rareThe line is a masterstroke of noncommitment, for the event is a "selly" in the sight of some unidentified readers. — 1995 formssellies · more selly · sellier · most selly · selliest