The scent of freshly-mowed grass is the lawn actually trying to save itself from injury by releasing a number of volatile organic compounds.
The Lawn must be trimmed weekly unless the owner intends to grow a miniature prairie, which supports a multitude of wildlife and billows wonderfully in the wind, but tends to incite class-action lawsuits by one's less imaginative neighbors.
A Lawn is a patch of manicured grass that you can only get a boy to stay off by asking him to mow it.
Dandelions are regarded as weeds today due to the rise of lawn culture and marketing by pesticide companies.
The Lawn is impossible to keep clear of crabgrass. The stuff can grow on bowling balls in airless rooms, and there is no known way to kill it that does not involve nuclear weapons.

The Lawn is the natural house-to-house carpeting, available only in a single shade of green.
Lawns before WWII were usually a mix of grass and clover. Herbicide companies in the 50s mounted a major advertising campaign to convince homeowners clover was a weed, because their new herbicides killed clover but not grass