What is the meaning of Reason?

A cause:

That which causes something: an efficient cause, a proximate cause.

A motive for an action or a determination.

An excuse: a thought or a consideration offered in support of a determination or an opinion; that which is offered or accepted as an explanation.

A premise placed after its conclusion.

Rational thinking (or the capacity for it); the cognitive faculties, collectively, of conception, judgment, deduction and intuition.

Something reasonable, in accordance with thought; justice.

Ratio; proportion.

To deduce or come to a conclusion by being rational.

To perform a process of deduction or of induction, in order to convince or to confute; to argue.

To converse; to compare opinions.

To arrange and present the reasons for or against; to examine or discuss by arguments; to debate or discuss.

To support with reasons, as a request.

To persuade by reasoning or argument.

To overcome or conquer by adducing reasons.

To find by logical process; to explain or justify by reason or argument.

A wall plate.

Source: wiktionary.org