One who does not regularly attend a venue.
A soldier who is not a member of an official military force and who may not use regular army tactics.
without symmetry, regularity, or uniformity
rough
not regular; having sides that are not equal or angles that are not equal
whose faces are not all regular polygons (or are not equally inclined to each other)
nonstandard; not conforming to rules or expectations
not following the regular or expected patterns of inflection in a given language
Someone who lacks a partner or team.
Something that is different from others in the same category; odd one out.
A temporary crew member who joins a mission with an established crew.
An eccentric; weirdo.