reasoning (Noun) — Thinking that is coherent and logical.
reasoning (Adjective) — Endowed with the capacity to reason.
reasoning (Verb) — Decide by reasoning; draw or come to a conclusion. ex. "We reasoned that it was cheaper to rent than to buy a house"
reasoning (Verb) — Present reasons and arguments.
reasoning (Verb) — Think logically. ex. "The children must learn to reason"