Noob spelled backwards.
Although it does not mean the opposite of 'Noob', it has to do with the same idea. While a noob is someone lacking experience, therefore tey are rather terrible at whatever it may be, a boon is somebody with experience but for whatever reason, they are just as bad. A boon plays at the skill level of a noob but they do't have an excuse because they have experience in the field they are performing in.

boons are grassy lands like rural areas or the suburbs.

a person or object bearing similarities to the baboon

Boon is another term for cannabis and cannabis joints. Used by many in the east midlands area to describe there favorite plant.

a cigerette
origionating in Oakville, Ontario, but has spread to burlington and surrounding suburbs.

from Oakville, ON

a cigarette