As nouns the difference between fortitude and permanence

is that fortitude is mental or emotional strength that enables courage in the face of adversity while permanence is the state of being permanent.

Popularity is a synonym of regard.

In archaic|lang=en terms the difference between popularity and regard

is that popularity is (archaic) public sentiment; general passion while regard is (archaic) to take notice of, pay attention to.

In obsolete|lang=en terms the difference between popularity and regard

is that popularity is (obsolete) the act of courting the favour of the people while regard is (obsolete) to set store by (something), to hold (someone) in esteem; to consider to have value, to respect.

As nouns the difference between popularity and regard

is that popularity is the quality or state of being popular; especially, the state of being esteemed by, or of being in favor with, the people at large; good will or favor proceeding from the people; as, the popularity of a law, statesman, or a book while regard is a steady look, a gaze.

As a verb regard is

(obsolete) to set store by (something), to hold (someone) in esteem; to consider to have value, to respect.

Pester is a related term of coerce.

In lang=en terms the difference between pester and coerce

is that pester is to bother, harass or annoy persistently while coerce is to use force, threat, fraud, or intimidation in attempt to compel one to act against his will.

As verbs the difference between pester and coerce

is that pester is to bother, harass or annoy persistently while coerce is to restrain by force, especially by law or authority; to repress; to curb.

Outbreak is a related term of inception.

As nouns the difference between outbreak and inception

is that outbreak is an eruption, sudden appearance while inception is the creation or beginning of something; the establishment.

As a verb outbreak

is to burst out.

Benignity is a related term of gratuity.

As nouns the difference between benignity and gratuity

is that benignity is (uncountable) the state of being benign while gratuity is a reward, service, or payment provided freely, without obligation.

Secret is a related term of shady.

As adjectives the difference between secret and shady

is that secret is being or kept hidden while shady is abounding in shades.

As a noun secret

is (countable|uncountable) knowledge that is hidden and intended to be kept hidden.

As a verb secret

is to make or keep secret.

Nefarious is a synonym of unmentionable.

As adjectives the difference between nefarious and unmentionable

is that nefarious is sinful, villainous, criminal, or wicked, especially when noteworthy or notorious for such characteristics while unmentionable is not mentionable.

Chivalrous is a related term of mythological.

As adjectives the difference between chivalrous and mythological

is that chivalrous is (of a man) honourable, especially to women while mythological is of, or relating to myths or mythology.

Unrestrained is a related term of unmanageable.

As adjectives the difference between unrestrained and unmanageable

is that unrestrained is immoderate; not restrained or held in check while unmanageable is not manageable; not readily submitting to handling or management; not easily restrained, governed, or directed; not controllable.

Squabble is a related term of struggle.

As nouns the difference between squabble and struggle

is that squabble is a minor fight or argument as between children, for example while struggle is strife, contention, great effort.

As verbs the difference between squabble and struggle

is that squabble is to participate in a minor fight or argument while struggle is to strive, to labour in difficulty, to fight (for'' or ''against ), to contend.