as to make it vacuously hold

Well, vacuous means, empty, devoid of purpose.

Oristar, I can't make neither heads nor tails of that whole sentence. Maybe someone with a more nimble mind would like to translate it for me!

I'm with Phoenix!

It seems to me that the writer does not think much of the definition of 'relevance' in Relevance Theory (q.v.), as it is rather mindlessly ('vacuously') all-inclusive, defined as including any communicative act that could possibly be interpreted as such.

for something to hold vacuously means that it is vacuously true

for a statement to be vacuously true, it means that the preconditions of the statement will never be met, so the conclusion of the statement is said to always be true since it is not false

for example, it is vacuously true to say that all flying elephants are pink, because there are no flying elephants