Adjective
(informal) Acting suspiciously; strange, unusual; acting in a manner as if having something to hide, or seemingly crooked.
(informal) Suspicious (of something).
(informal) dishonest; sketchy; shady
(informal, derogatory) Weird; nonstandard.
(informal) unreliable; wonky
(informal) snobbish; haughty
Source: en.wiktionary.org