As adjectives the difference between changeable and unsteady

is that changeable is capable of being changed while unsteady is not held firmly in position, physically unstable.

As a verb unsteady is

to render unsteady, removing balance.

As adjectives the difference between beastly and barbarous

is that beastly is pertaining to, or having the form, nature, or habits of, a beast while barbarous is not classical or pure.

As an adverb beastly

is like a beast; brutishly.

In transitive terms the difference between model and mint

is that model is to create from a substance such as clay while mint is to reproduce (coins), usually en masse, under licence.

As nouns the difference between cask and drum

is that cask is a large barrel for the storage of liquid, especially of alcoholic drinks while drum is a percussive musical instrument spanned with a thin covering on at least one end for striking, forming an acoustic chamber, affecting what materials are used to make it.

As verbs the difference between cask and drum

is that cask is to put into a cask while drum is to beat a drum.

In transitive terms the difference between manipulate and ply

is that manipulate is to influence, manage, direct, control or tamper with something while ply is to persist in offering.

As a noun ply is

a layer of material.

Cantankerous is a related term of unkind.

As adjectives the difference between cantankerous and unkind

is that cantankerous is given to or marked by an ill-tempered nature, ill-tempered, cranky, surly, crabby while unkind is (obsolete) having no race or kindred; childless.

Medium is a synonym of common.

As nouns the difference between medium and common

is that medium is medium while common is mutual good, shared by more than one.

As an adjective common is

mutual; shared by more than one.

As a verb common is

(obsolete) to communicate (something).

Litter is a synonym of bed.

As a noun litter

is (countable) a platform mounted on two shafts, or a more elaborate construction, designed to be carried by two (or more) people to transport one (in luxury models sometimes more) third person(s) or (occasionally in the elaborate version) a cargo, such as a religious idol.

As a verb litter

is to drop or throw trash without properly disposing of it (as discarding in public areas rather than trash receptacles).

In intransitive terms the difference between haggle and quibble

is that haggle is to argue for a better deal, especially over prices with a seller while quibble is to complain or argue in a trivial or petty manner.

As a noun quibble is

a trivial or minor complaint, objection or argument.

Contrivance is a synonym of plot.

As nouns the difference between contrivance and plot

is that contrivance is a (mechanical) device to perform a certain task while plot is the course of a story, comprising a series of incidents which are gradually unfolded, sometimes by unexpected means.

As a verb plot is

to conceive (a crime, etc).