Verb

• S: (v) reason, reason out, conclude (decide by reasoning; draw or come to a conclusion) "We reasoned that it was cheaper to rent than to buy a house"
• S: (v) argue, reason (present reasons and arguments)
• S: (v) reason (think logically) "The children must learn to reason"

Adjective

• S: (adj) reasoned, sound, well-grounded (logically valid) "a sound argument"
• similar to
• derivationally related form
• antonym