What does "nullifidian" mean?

A sceptic; an atheist or unbeliever.

What is a synonym for "nullifidian"?

Common synonyms include: atheist, atheistic, disbelieving, faithless, gentile, godless.

Pronounced //ˌnʌl.əˈfɪd.i.ən//.

/ˌnʌl.əˈfɪd.i.ən/ adj, noun

adj, noun ·Rare ·Advanced level

Noun

1
A sceptic; an atheist or unbeliever. archaic
"Near-synonyms: infidel, apostate, heretic (either coordinate or synonymous depending on the beliefs of the speaker or writer)"

Adjective

1
Of no faith or religion; not trusting to faith for salvation.
"Near-synonyms: atheistic, agnostic"

"Near-synonyms: infidel, apostate, heretic (either coordinate or synonymous depending on the beliefs of the speaker or writer)"

From Latin nūllus (“not any”) + fidēs (“faith”) + -ian.