[Olog-hai]

Fallacious attempt at turnaround. Dictionaries hold definitions of words, not redefinitions, and are not authorities in the sense of argumentum ad verecundiam but references.

Not to mention that repeatedly doubling down on the aforementioned logical fallacy still will not remove its fallaciousness.

[who_would_fardels_bear]

Dictionary definition of valid as used by philosophers:

Dictionary of Philosophy - V

[who_would_fardels_bear]

Valid inference: In common usage an inference is said to be valid if it is permitted by the laws of logic. It is possible to specify this more exactly only in formal terms, with reference to a particular logistic system (q.v.).

The question of the validity of an inference from a set of premisses is, of course, independent of the question of the truth of the premisses. -- A.C.

[who_would_fardels_bear]

Or this...

Oxford Dictionary of Philosophy

You can only see the first few words without a subscription, but it is clear that this sentence goes:

In its primary meaning it is arguments that are valid or invalid, according to whether the conclusion follows from the premisses. (my supposition)

i.e. it has nothing to do with whether or not the premisses are true. Only whether or not the argument is logical.