As an adjective invisible

is unable to be seen; out of sight; not visible.

As a proper noun ringwraith is

(fantasy) anyone who keeps a magical ring, and is enslaved thereby, and may also be rendered invisible and immortal thereby.

As nouns the difference between immortal and ringwraith

is that immortal is one who is not susceptible to death while ringwraith is figuratively, a person who is loyal as if bound or entranced to a rock and roll band, group or organization.

As an adjective immortal

is not susceptible to death; living forever; never dying.

As a proper noun Ringwraith is

anyone who keeps a magical ring, and is enslaved thereby, and may also be rendered invisible and immortal thereby.

Nazgul is a synonym of ringwraith.

As a noun nazgul

is an evil force which heedlessly destroys everything in its path, and appears like a horseman dressed all in black or nazgul can be .

As a proper noun ringwraith is

(fantasy) anyone who keeps a magical ring, and is enslaved thereby, and may also be rendered invisible and immortal thereby.

Nil is a initialism of npo.

As initialisms the difference between nil and npo

is that nil is (nanotechnology) (nanoimprint lithography) while npo is (medicine) "nil per os" (nothing by mouth - nothing may be eaten or drunk).

Cytosome is a derived term of cytosomal.

Cytosomal is often a misspelling of cytosome.

Cytosomal has no English definition.

As a noun cytosome is

the cytoplasm within a cell; the cell outside of the nucleus.

Cytosomic is a derived term of cytosome.

As a noun cytosome is

(biology|uncountable) the cytoplasm within a cell; the cell outside of the nucleus.

Cytosome is a related term of cytosegresome.

Cytosegresome is likely misspelled.

Cytosegresome has no English definition.

As a noun cytosome is

the cytoplasm within a cell; the cell outside of the nucleus.

As adjectives the difference between excruciating and superexcruciating

is that excruciating is causing great pain or anguish, agonizing while superexcruciating is (rare) very excruciating.

In lang=en terms the difference between obligation and obligator

is that obligation is a legal agreement stipulating a specified payment or action; the document containing such agreement while obligator is one who establishes an obligation under law.

As nouns the difference between obligation and obligator

is that obligation is the act of binding oneself by a social, legal, or moral tie to someone while obligator is one who establishes an obligation under law.

Agent is a coordinate term of obligator.

As nouns the difference between agent and obligator

is that agent is agent (intermediary for certain services, such as for artistic performances or public relations) while obligator is (legal) one who establishes an obligation under law.