reason

Sense 1 noun

a rational motive for a belief or action

the reason that war was declared

Sense 2 verb

decide by reasoning; draw or come to a conclusion

We reasoned that it was cheaper to rent than to buy a house

Sense 3 noun

an explanation of the cause of some phenomenon

the reason a steady state was never reached was that the back pressure built up too slowly

Sense 4 verb

present reasons and arguments

Sense 5 noun

the capacity for rational thought or inference or discrimination

we are told that man is endowed with reason and capable of distinguishing good from evil

Sense 6 verb

think logically

The children must learn to reason

Sense 7 noun

the state of having good sense and sound judgment

his rationality may have been impaired

Sense 8 noun

a justification for something existing or happening

he had no cause to complain

Sense 9 noun

a fact that logically justifies some premise or conclusion

there is reason to believe he is lying