As adjectives the difference between prolific and reproductive

is that prolific is fertile, producing offspring or fruit in abundance — applied to plants producing fruit, animals producing young, etc while reproductive is of or relating to reproduction.

As a noun reproductive is

a reproductive organism (especially such as in an insect).

Vigilant is a related term of keen.

As adjectives the difference between vigilant and keen

is that vigilant is watchful, especially for danger or disorder; alert; wary while keen is showing a quick and ardent willingness or responsiveness, enthusiastic, eager; interested, intense.

As a verb keen is

(rare) to sharpen; to make cold or keen can be to utter a keen.

As a noun keen is

a prolonged wail for a deceased person.

Pelisse is a related term of serape.

As nouns the difference between pelisse and serape

is that pelisse is a fur-lined or fur robe or gown, especially as part of a uniform while serape is a type of blanket worn as a cloak, especially by spanish-americans.

Union is a related term of assortment.

As nouns the difference between union and assortment

is that union is union (action and result) while assortment is a collection of varying but related items.

Frigid is a synonym of austere.

As adjectives the difference between frigid and austere

is that frigid is very cold; lacking warmth; icy while austere is austere.

Remarkably is a related term of peculiarly.

As adverbs the difference between remarkably and peculiarly

is that remarkably is (manner) in a remarkable manner while peculiarly is such as to be greater than usual; particularly; exceptionally.

Unmoved is a related term of calculating.

As adjectives the difference between unmoved and calculating

is that unmoved is not physically moved while calculating is (especially of a robot) which has the ability to calculate.

As a verb calculating is

.

Unpleasant is a related term of heinous.

As adjectives the difference between unpleasant and heinous

is that unpleasant is not pleasant while heinous is totally reprehensible.

Intimation is a related term of foretoken.

As nouns the difference between intimation and foretoken

is that intimation is the act of intimating; also, the thing intimated while foretoken is a prognostic; a premonitory sign; warning or presentment.

As a verb foretoken is

to betoken beforehand; prognosticate; foreshadow; give warning; presage.

As nouns the difference between derision and disfavour

is that derision is act of treating with disdain while disfavour is the state of being out of favour.

As a verb disfavour is

to show lack of favour or antipathy towards.