if two things are interchangeable, you can put each one of them in the place where the other was, or you can use one instead of the other, and the effect will be the same
The terms ‘thesis’ and ‘dissertation’ were at one time interchangeable.
Synonyms and related words
The same
another
equal
equivalent
derived words
interchangeability
noun
Synonyms and related words
The quality of being similar or the same
similarity
sameness
likeness
interchangeably
adverb
Synonyms and related words
The same
another
equal
equivalent
interchangeable
adjective
US /ˌɪntərˈtʃeɪndʒəb(ə)l/
DEFINITIONS1
1
if two things are interchangeable, you can put each one of them in the place where the other was, or you can use one instead of the other, and the effect will be the same
“Thesis” and “dissertation” were at one time totally interchangeable.