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 is eccentric, nonconformist, or otherwise peculiar.
Someone who is easily fooled, victimized, or ridiculed.
A person, thing, or situation which is particularly interesting, noteworthy, or urgent.