Seemingly well-reasoned, plausible or true, but actually fallacious. / Employing fallacious but deceptively plausible arguments; deceitful.

The time duration wherein one's perceptions are considered to be in the present.

(uncountable) The state or quality of being specious. / (countable, rare) The result or product of being specious.

In a specious manner; fallaciously and erroneously, but seeming superficially to be correct.

plural of speciousness