frivolous

As adjectives the difference between frivolous and unique

is that frivolous is silly, especially at an inappropriate time or in an inappropriate manner while unique is (not comparable) being the only one of its kind; unequaled, unparalleled or unmatched.

As a noun unique is

a thing without a like; something unequalled or unparallelled.

As adjectives the difference between cogent and frivolous

is that cogent is reasonable and convincing; based on evidence while frivolous is silly, especially at an inappropriate time or in an inappropriate manner.

Unprofitable is a related term of frivolous.

As adjectives the difference between unprofitable and frivolous

is that unprofitable is not making a profit while frivolous is silly, especially at an inappropriate time or in an inappropriate manner.

As adjectives the difference between frivolous and vapid

is that frivolous is silly, especially at an inappropriate time or in an inappropriate manner while vapid is lifeless, dull or banal.

As adjectives the difference between futile and frivolous

is that futile is incapable of producing results; useless; not successful; not worth attempting while frivolous is silly, especially at an inappropriate time or in an inappropriate manner.

Feeble is a related term of frivolous.

As adjectives the difference between feeble and frivolous

is that feeble is deficient in physical strength; weak; infirm; debilitated while frivolous is silly, especially at an inappropriate time or in an inappropriate manner.

As a verb feeble

is (obsolete) to make feeble; to enfeeble.

Profitless is a related term of frivolous.

As adjectives the difference between profitless and frivolous

is that profitless is not yielding profit while frivolous is silly, especially at an inappropriate time or in an inappropriate manner.

Useless is a related term of frivolous.

As adjectives the difference between useless and frivolous

is that useless is without use or possibility to be used while frivolous is silly, especially at an inappropriate time or in an inappropriate manner.

Insolent is a related term of frivolous.

As adjectives the difference between insolent and frivolous

is that insolent is insulting in manner or words while frivolous is silly, especially at an inappropriate time or in an inappropriate manner.

As adjectives the difference between ineffectual and frivolous

is that ineffectual is unable or insufficient to produce effect; futile while frivolous is silly, especially at an inappropriate time or in an inappropriate manner.