A field of cultivated and mowed grass WordNet 3.0 & Open English WordNet

A lawn is an area of soil-covered land planted with grasses and other durable plants such as clover which are maintained at a short height with a lawn mower and used for aesthetic and recreational purposes—it is also commonly referred to as part of a garden. Wikipedia

Area of land planted with grass and sometimes clover and other plants, which are maintained at a low, even height. Wikipedia Disambiguation

A ground covered with grass kept closely mown. OmegaWiki

Ground (generally in front of or around a house) covered with grass kept closely mown. Wiktionary

Ground covered with grass. Wiktionary (translation)