arcane

As an adjective arcane

is understood by only a few; obscure; requiring secret or mysterious knowledge.

As a letter x is

the twenty-fourth letter of the.

As a symbol x is

voiceless velar fricative.

As adjectives the difference between esoterica and arcane

is that esoterica is while arcane is understood by only a few; obscure; requiring secret or mysterious knowledge.

As adjectives the difference between convival and arcane

is that convival is (obsolete) relating to a feast or festivity; convivial while arcane is understood by only a few; obscure; requiring secret or mysterious knowledge.

As adjectives the difference between arcane and hermetic

is that arcane is understood by only a few; obscure; requiring secret or mysterious knowledge while hermetic is (chiefly with capital initial) pertaining to (hermes trismegistus) or the writings attributed to him.

As a noun hermetic is

(in plural) hermetic philosophy or practice.

As adjectives the difference between arcane and obsolete

is that arcane is understood by only a few; obscure; requiring secret or mysterious knowledge while obsolete is obsolete, deprecated (computing).

As adjectives the difference between arcane and false

is that arcane is understood by only a few; obscure; requiring secret or mysterious knowledge while false is (label) one of two states of a boolean variable; logic.

As adjectives the difference between arcane and progressive

is that arcane is understood by only a few; obscure; requiring secret or mysterious knowledge while progressive is belonging to or supporting a.

As a noun progressive is

a member or supporter of a.

As adjectives the difference between arcane and undefined

is that arcane is understood by only a few; obscure; requiring secret or mysterious knowledge while undefined is lacking a definition or value.

As adjectives the difference between arcane and equivocal

is that arcane is understood by only a few; obscure; requiring secret or mysterious knowledge while equivocal is having two or more equally applicable meanings; capable of double or multiple interpretation; ambiguous; uncertain.

As a noun equivocal is

a word or expression capable of different meanings; an ambiguous term; an equivoque.

As adjectives the difference between opaque and arcane

is that opaque is neither reflecting nor emitting light while arcane is understood by only a few; obscure; requiring secret or mysterious knowledge.

As a noun opaque

is an area of darkness; a place or region with no light.

As a verb opaque

is to make, render (more) opaque.