Orky is a term used in the Warhammer Universe (or Ooniverse, to be Orky) by Orks to describe something worthy of being used by, ridden in, said by, or otherwise being associated with Orks.
Most Orky words starting with or using a C will have the C replaced, as in Trukk (truck) and Kulture (culture).
The same applies for the letter S in words like Boyz (boys) and Gunz (guns).
Something can be made Orky through either adding red paint (yellow can be substituted, as it is a roight snazzy kulah), adding some stompy bitz, or the traditional method of simply adding more DAKKA. Nevah enuff dakka.
Devastator Marine: FOR THE EMPEROR! DIE FILTHY XENOS!
Slugga boy: OI, dat 'umie's got sum roight Orky dakka! Let'z loot it!
Ork: OI, whacha think about me Wartrukk?
Second Ork: Not orky enuff! Needz more dakka dakka dakka! Nevah enuff dakka!
First Ork: WHAT!? OI! Yer right! More Dakka it is!
Ork: Oi, some git thought Orky ment "dorky".
Nob: Yeh. Warboss Bonestomp 'ad ta come in and fix it, Make it roight propah an' Orky.