Excessively subtle; overly ingenious or intricate.

Minute in inquiry or discrimination, subtle.

depreciative. Of reasoning, ideas, etc.: excessively subtle or abstract.

Metaphysical.

Of a person, the mental faculties, or intellectual activity: characterized by wisdom or perceptiveness; discriminating, discerning; shrewd.

That makes fine distinctions; given to or characterized by subtle argument or reasoning.

That ‘splits hairs’; that makes over-nice distinctions, over-refining.

(see split, v. 5b and cf. hair-splitter, n., straw-splitting n. adj.).

Of, resembling, or designating subtle or keen rabbinical argumentation. In extended use: subtle, quibbling, pedantic.