adjective. Not adhering to convention; out of the ordinary.

Not conventional; not bound by unswerving rules; free in character, action, or treatment.

adjective. Not adhering to convention or accepted standards

adjective. Out of the ordinary

adjective. Atypical

noun. Something or someone that is unconventional.

adjective. not conventional or conformist

adjective. not conforming to accepted rules or standards

adjective. not conforming to legality, moral law, or social convention

"The term unconventional resources is applied to a broad category of fuels like shale gas, tar sands and other forms of oil and gas that require sophisticated technology to extract and are typically more expensive to develop."

conventional  customary  stiff  

informal  

alternative  bizarre  bohemian  devil-may-care  eccentric  

conventional  dimensional  intentional  unintentional  

amuse  bizarre  contradictory  eccentric  erratic  

Bohemian  abnormal  affable  anomalous  beat