Absolutely is a related term of demonstrably.
As adverbs the difference between absolutely and demonstrably
is that absolutely is in an absolute or unconditional manner; utterly, positively, wholly while demonstrably is in such a manner as to be capable of being demonstrated, shown or proved.
As an interjection absolutely
is yes; certainly; expression indicating strong agreement [. ]
absolutely
English
Adverb
(-)
In an absolute or unconditional manner; utterly, positively, wholly.
Independently; viewed without relation to other things or factors. [ ]
(grammar) In a manner that does not take an object.
Usage notes
* Absolutely'' is not to be confused with intensives such as ''very'' or ''indeed , as it is an unconditional term.
Interjection
(
en interjection)
Yes; certainly; expression indicating strong agreement. [ ]
Usage notes
* Some commentators, especially in England, criticise the interjectional use as having no useful meaning beyond that of yes;[, page 3] however, this assumes that emphasis is useless, which, pragmatically speaking, it isn’t.
References
demonstrably
English
Adverb
(
en adverb)
In such a manner as to be capable of being demonstrated, shown or proved.