Illustrious is a synonym of signal.

As an adjective illustrious

is dignified.

As a noun signal is

signal.

Lower is a related term of decay.

In lang=en terms the difference between lower and decay

is that lower is to decrease in value, amount, etc while decay is to cause to rot or deteriorate.

As verbs the difference between lower and decay

is that lower is to let descend by its own weight, as something suspended; to let down or lower can be while decay is to deteriorate, to get worse, to lose strength or health, to decline in quality.

As an adjective lower

is (low).

As an adverb lower

is .

As a noun decay is

the process or result of being gradually decomposed.

As verbs the difference between inform and mutter

is that inform is to instruct, train (usually in matters of knowledge) while mutter is to utter words, especially complaints or angry expressions, indistinctly or with a low voice and lips partly closed; to say under one's breath.

As an adjective inform

is without regular form; shapeless; ugly; deformed.

As a noun mutter is

a repressed or obscure utterance; an instance of muttering.

As verbs the difference between harden and condense

is that harden is to become hard (tough, resistant to pressure) while condense is to decrease size or volume by concentration toward the essence.

As an adjective condense is

condensed; compact; dense.

Skedaddle is a related term of glide.

As verbs the difference between skedaddle and glide

is that skedaddle is to move or run away quickly while glide is to move softly, smoothly, or effortlessly.

As a noun glide is

the act of gliding.

As nouns the difference between splendor and brilliancy

is that splendor is great light, luster or brilliance while brilliancy is a shining quality; brilliance.

Vitiated is a related term of profligate.

As verbs the difference between vitiated and profligate

is that vitiated is (vitiate) while profligate is (obsolete) to drive away; to overcome.

As an adjective profligate is

(obsolete) overthrown, ruined.

As a noun profligate is

an abandoned person; one openly and shamelessly vicious; a dissolute person.

In transitive terms the difference between decry and depreciate

is that decry is to blame for ills while depreciate is to belittle.

Menial is a related term of despicable.

As adjectives the difference between menial and despicable

is that menial is of or relating to work normally performed by a servant while despicable is fit or deserving to be despised; contemptible; mean; vile; worthless.

As a noun menial

is a servant, especially a domestic servant.