Aeration
Perforating soil to allow air, water and nutrients to reach grass roots. (You can rent aerators from the hardware store— the core variety is most effective.)

Dethatching
Removing thatch (the buildup of dried cut grass leaves) with a power rake, or dethatcher.

Turfgrass
The correct name for narrow-leaved grass that's grown as a lawn.

Overseeding
Adding fresh grass seed to an existing lawn, usually to fill in sections that have been damaged by diseases, insects or animals.

Fescue
Narrow-leaved grass species that are drought-tolerant and typically don't need frequent mowing.

Taproot
A downward-growing root (as opposed to a fibrous root system). Thistle and dandelion roots are prime examples.

Read more:
Your guide to the most gorgeous lawn ever
5 easy, all-natural ways to keep your lawn weed-free