irregular

Irregular is a related term of periodic.

As an adjective irregular

is irregular.

As a noun periodic is

newspaper.

Sundry is a related term of irregular.

As adjectives the difference between sundry and irregular

is that sundry is (obsolete) separate; distinct; diverse while irregular is irregular.

As a noun sundry

is (usually|in the plural) a minor miscellaneous item.

Irregular is a related term of flighty.

As adjectives the difference between irregular and flighty

is that irregular is irregular while flighty is given to unplanned and silly ideas or actions.

As adjectives the difference between irregular and unsteady

is that irregular is nonstandard; not conforming to rules or expectations while unsteady is not held firmly in position, physically unstable.

As a noun irregular

is a soldier who is not a member of an official military force and, often, does not follow regular army tactics.

As a verb unsteady is

to render unsteady, removing balance.

As an adjective irregular is

irregular.

Unique is a related term of irregular.

As adjectives the difference between unique and irregular

is that unique is (not comparable) being the only one of its kind; unequaled, unparalleled or unmatched while irregular is irregular.

As a noun unique

is a thing without a like; something unequalled or unparallelled.

Irregular is a related term of oddball.

As adjectives the difference between irregular and oddball

is that irregular is irregular while oddball is exotic, not mainstream, such as an oddball word or an oddball computer program.

As a noun oddball is

an eccentric or unusual person.

Irregular is a synonym of peculiar.

As adjectives the difference between irregular and peculiar

is that irregular is irregular while peculiar is out of the ordinary; odd; curious; unusual.

As a noun peculiar is

that which is peculiar; a sole or exclusive property; a prerogative; a characteristic.

As adjectives the difference between desultory and irregular

is that desultory is jumping, or passing, from one thing or subject to another, without order or rational connection; without logical sequence while irregular is nonstandard; not conforming to rules or expectations.

As a noun irregular is

a soldier who is not a member of an official military force and, often, does not follow regular army tactics.