As adjectives the difference between rigorous and responsible

is that rigorous is manifesting, exercising, or favoring rigour; allowing no abatement or mitigation; scrupulously accurate; exact; strict; severe; relentless; as, a rigorous officer of justice; a rigorous execution of law; a rigorous definition or demonstration while responsible is answerable for an act performed or for its consequences; accountable; amenable, especially legally or politically.

Nicely is a synonym of attractively.

As adverbs the difference between nicely and attractively

is that nicely is (obsolete) fastidiously; carefully while attractively is in an attractive manner; with the power of attracting or drawing to.

As nouns the difference between cumulation and assortment

is that cumulation is accumulation while assortment is a collection of varying but related items.

As adjectives the difference between ungainly and extensive

is that ungainly is clumsy; lacking grace while extensive is in the nature of an extent, wide, widespread.

Nick is a related term of rive.

As a proper noun nick

is a diminutive of the male given name nicholas.

As a verb rive is

.

Infamous is a related term of wicked.

As adjectives the difference between infamous and wicked

is that infamous is having a bad reputation, disreputable; of bad report; notoriously vile; detestable; widely known, especially for something bad while wicked is evil or mischievous by nature or wicked can be having a wick.

As an adverb wicked is

(slang|new england|british) very, extremely.

As a noun wicked is

people who are wickedoxford dictionary [http://wwwoxfordadvancedlearnersdictionarycom/dictionary/wicked_2].

As a verb wicked is

(wick).

Continuance is a synonym of perseverance.

As nouns the difference between continuance and perseverance

is that continuance is (uncountable) the action of continuing while perseverance is perseverance (persistent determination to adhere to a course of action; insistence).

Celebrate is a synonym of bless.

As a verb celebrate

is to extol or honour in a solemn manner.

As a noun bless is

injury, wound.

As adjectives the difference between protective and indulgent

is that protective is serving, intended or wishing to protect while indulgent is disposed or prone to indulge, humor, gratify, or give way to one's own or another's desires, etc., or to be compliant, lenient, or forbearing; showing or ready to show favor; favorable; indisposed to be severe or harsh, or to exercise necessary restraint: as, an indulgent parent; to be indulgent to servants.

As a noun protective

is something that protects.

Rain is a synonym of lavish.

As a noun rain

is .

As an adjective lavish is

expending or bestowing profusely; profuse; prodigal.

As a verb lavish is

to expend or bestow with profusion; to use with prodigality; to squander; as, to lavish money or praise.