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1.

1. Having a kind and gentle disposition or appearance.

2. Not a threat to life or long-term health, especially by being noncancerous.

3. Neutral or harmless in its effect or influence.

4. Mild or favorable in effect.

1. The lady next door is a relavively benign presence.
2. The cancer's benign.
3. The storm was benign.
by Jafje September 11, 2007
 
2.
verb. the age one becomes after eight.
joe will benign after his birthday next week.
by mark86 May 19, 2005