As verbs the difference between desire and option

is that desire is to want; to wish for earnestly while option is to purchase an option on something.

As nouns the difference between desire and option

is that desire is someone or something wished for while option is one of the choices which can be made.

Regular is a related term of unalterable.

As adjectives the difference between regular and unalterable

is that regular is while unalterable is incapable of changing or being altered.

As an adverb regular

is regularly.

Case is a synonym of debate.

As nouns the difference between case and debate

is that case is (label) abstract feature of a noun phrase that determines its function in a sentence, such as a grammatical case and a position while debate is (obsolete) strife, discord.

As a verb debate is

(ambitransitive) to participate in a debate; to dispute, argue, especially in a public arena.

Mensuration is a related term of estimation.

As nouns the difference between mensuration and estimation

is that mensuration is the branch of mathematics that deals with measurement, especially the derivation and use of algebraic formulae to measure the areas, volumes and different parameters of geometric figures while estimation is the process of making an estimate.

Thought is a related term of preoccupation.

As nouns the difference between thought and preoccupation

is that thought is form created in the mind, rather than the forms perceived through the five senses; an instance of thinking while preoccupation is worry.

As a verb thought

is (think).

Tamely is a related term of moderately.

As adverbs the difference between tamely and moderately

is that tamely is in a tame manner while moderately is in a moderate manner.

Contrivance is a related term of utensils.

As nouns the difference between contrivance and utensils

is that contrivance is a (mechanical) device to perform a certain task while utensils is .

Madden is a related term of chafe.

As a proper noun madden

is .

As a verb chafe is

.

Hateful is a related term of inappropriate.

As adjectives the difference between hateful and inappropriate

is that hateful is evoking a feeling of hatred while inappropriate is not appropriate; not suitable for the situation, time, and/or place.

Conviction is a related term of speculation.

As nouns the difference between conviction and speculation

is that conviction is (countable) a firmly held belief while speculation is speculation.