true

Conforming to the actual state of reality or fact; factually correct.

As an ellipsis of "(while) it is true (that)", used to start a sentence

Conforming to a rule or pattern; exact; accurate.

Of the state in Boolean logic that indicates an affirmative or positive result.

Loyal, faithful.

Genuine; legitimate; valid; sensu stricto.

Used in the designation of group of species, or sometimes a single species, to indicate that it belongs to the clade its common name (which may be more broadly scoped in common speech) is restricted to in technical speech, or to distinguish it from a similar species, the latter of which may be called false.

Accurate; following a path toward the target.

Correctly aligned or calibrated, without deviation.

Fair, unbiased, not loaded.