at home is an adverb and noun meaning "on the home team's field". It carries 3 recorded senses.
on the home team's field
“they played at home last night”
sport
at, to, or toward the place where you reside
“he worked at home”
a reception held in your own home
Definitions, synonyms and semantic relations for at home come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.