To support with reasons, as a request.

To persuade by reasoning or argument; as, to reason one
into a belief; to reason one out of his plan.

Ratio; proportion.

To converse; to compare opinions.

To exercise the rational faculty; to deduce inferences from
premises; to perform the process of deduction or of induction; to
ratiocinate; to reach conclusions by a systematic comparison of facts.

Due exercise of the reasoning faculty; accordance with, or
that which is accordant with and ratified by, the mind rightly
exercised; right intellectual judgment; clear and fair deductions from
true principles; that which is dictated or supported by the common
sense of mankind; right conduct; right; propriety; justice.

A thought or a consideration offered in support of a
determination or an opinion; a just ground for a conclusion or an
action; that which is offered or accepted as an explanation; the
efficient cause of an occurrence or a phenomenon; a motive for an
action or a determination; proof, more or less decisive, for an opinion
or a conclusion; principle; efficient cause; final cause; ground of
argument.

i. neden, sebep. What’s the reason of this delay? (Bu gecikmenin nedeni nedir?)

The faculty or capacity of the human mind by which it is
distinguished from the intelligence of the inferior animals; the higher
as distinguished from the lower cognitive faculties, sense,
imagination, and memory, and in contrast to the feelings and desires.
Reason comprises conception, judgment, reasoning, and the intuitional
faculty. Specifically, it is the intuitional faculty, or the faculty of
first truths, as distinguished from the understanding, which is called
the discursive or ratiocinative faculty.

Hence: To carry on a process of deduction or of induction,
in order to convince or to confute; to formulate and set forth
propositions and the inferences from them; to argue.