"NATURAL BUFFER" shall mean a space between the buildings, parking areas and uses on a lot and the lot line in which numerous trees exist, which is cleared of all rubbish and waste material, and which is sufficiently dense so as to obstruct the direct vision of the buildings, parking areas or uses on the lot on which it is located of a person standing on the adjacent lot not closer than 25 feet from the lot line.

"NURSERY SCHOOL" shall mean the providing of daytime care or instructions for not more than 15 children from two to five years in age, inclusive. Schools or places providing instruction or day care for more than 15 children or for children six years of age or older shall be considered private schools.