momentous

As a noun moment

is moment or moment can be momentum.

As an adjective momentous is

outstanding in importance, of great consequence.

Heavy is a related term of momentous.

As adjectives the difference between heavy and momentous

is that heavy is (of a physical object) having great weight or heavy can be having the heaves while momentous is outstanding in importance, of great consequence.

As an adverb heavy

is heavily.

As a noun heavy

is a villain or bad guy; the one responsible for evil or aggressive acts.

As a verb heavy

is to make heavier.

Staid is a related term of momentous.

As a noun staid

is trail, track or staid can be stately woman.

As an adjective momentous is

outstanding in importance, of great consequence.

Momentous is a related term of necessary.

As adjectives the difference between momentous and necessary

is that momentous is outstanding in importance, of great consequence while necessary is needed, required.

As a noun necessary is

(archaic|british) bathroom, toilet, loo.

Demure is a related term of momentous.

As adjectives the difference between demure and momentous

is that demure is quiet, modest, reserved, sober, or serious while momentous is outstanding in importance, of great consequence.

As a verb demure

is (obsolete) to look demurely.

Sedate is a related term of momentous.

As adjectives the difference between sedate and momentous

is that sedate is in a composed and temperate state while momentous is outstanding in importance, of great consequence.

As a verb sedate

is to tranquilize by giving a sedative; to calm; to soothe; to induce sleep.

Direct is a related term of momentous.

As adjectives the difference between direct and momentous

is that direct is straight, constant, without interruption while momentous is outstanding in importance, of great consequence.

As an adverb direct

is directly.

As a verb direct

is to manage, control, steer.

As adjectives the difference between momentous and high

is that momentous is outstanding in importance, of great consequence while high is elevated in position or status; above many things.

As a noun high is

thought; intention; determination; purpose.

As an adverb high is

in or to an elevated position.

As a verb high is

to rise.

As adjectives the difference between momentous and fundamental

is that momentous is outstanding in importance, of great consequence while fundamental is pertaining to the foundation or basis; serving for the foundation. Hence: Essential, as an element, principle, or law; important; original; elementary.

As a noun fundamental is

a leading or primary principle, rule, law, or article, which serves as the groundwork of a system; essential part, as, the fundamentals of linear algebra.

Solemn is a related term of momentous.

As adjectives the difference between solemn and momentous

is that solemn is deeply serious and somber while momentous is outstanding in importance, of great consequence.