efficacy

In uncountable terms the difference between efficacy and ability

is that efficacy is ability to produce a desired amount of a desired effect while ability is a unique power of the mind; a faculty.

Benefit is a related term of efficacy.

As nouns the difference between benefit and efficacy

is that benefit is an advantage, help, sake or aid from something while efficacy is (uncountable) ability to produce a desired amount of a desired effect.

As a verb benefit

is to be or to provide a benefit to.

As nouns the difference between efficacy and validity

is that efficacy is ability to produce a desired amount of a desired effect while validity is the state of being valid, authentic or genuine.

Efficacy is a related term of talent.

As nouns the difference between efficacy and talent

is that efficacy is (uncountable) ability to produce a desired amount of a desired effect while talent is talent.

Attainment is a related term of efficacy.

As nouns the difference between attainment and efficacy

is that attainment is the act of attaining; the act of arriving at or reaching; the act of obtaining by exertion or effort while efficacy is (uncountable) ability to produce a desired amount of a desired effect.

Worth is a related term of efficacy.

In uncountable|lang=en terms the difference between worth and efficacy

is that worth is (uncountable) merit, excellence while efficacy is (uncountable) ability to produce a desired amount of a desired effect.

As nouns the difference between worth and efficacy

is that worth is (countable) value while efficacy is (uncountable) ability to produce a desired amount of a desired effect.

As a preposition worth

is having a value of; proper to be exchanged for.

As a verb worth

is (obsolete|except in set phrases) to be, become, betide.

Design is a related term of efficacy.

As nouns the difference between design and efficacy

is that design is design (creative profession or art) while efficacy is (uncountable) ability to produce a desired amount of a desired effect.

Skill is a related term of efficacy.

As nouns the difference between skill and efficacy

is that skill is capacity to do something well; technique, ability skills are usually acquired or learned, as opposed to abilities, which are often thought of as innate while efficacy is (uncountable) ability to produce a desired amount of a desired effect.

As a verb skill

is to set apart; separate.

As an adjective skill

is (uk|slang) great, excellent.

Competency is a related term of efficacy.

As nouns the difference between competency and efficacy

is that competency is (obsolete) a sufficient supply (of) while efficacy is (uncountable) ability to produce a desired amount of a desired effect.