In Matthew 12:36, means empty and fruitless. The "idle word" which Christ condemns, is a word morally useless and evil.

I'DLE, a.

1. Not employed; unoccupied with business; inactive; doing nothing.

Why stand ye here all the day idle? Matt.20.

To be idle, is to be vicious.

2. Slothful; given to rest and ease; averse to labor or employment; lazy; as an idle man; an idle fellow.

3. Affording leisure; vacant; not occupied; as idle time; idle hours.

4. Remaining unused; unemployed; applied to things; as, my sword or spear is idle.

5. Useless; vain; ineffectual; as idle rage.

6. Unfruitful; barren; not productive of good.

Of antres vast and idle desarts.

Idle weeds.

7. Trifling; vain; of no importance; as an idle story; an idle reason; idle arguments.

8. Unprofitable; not tending to edification.

Every idle word that men shall speak,they shall give an account thereof in the day of judgment. Matt.12.

Idle differs from lazy; the latter implying constitutional or habitual aversion or indisposition to labor or action, sluggishness; whereas idle, in its proper sense, denotes merely unemployed. An industrious man may be idle, but he cannot be lazy.

I'DLE, v.i. To lose or spend time in inaction, or without being employed in business.

To idle away, in a transitive sense, to spend in idleness; as, to idle away time.