Flatulent is the adjective: a person, a stomach, or a feeling that has too much gas. You might read it on a medicine box or in a health article (flatulent after eating dairy). In ordinary speech almost nobody says I feel flatulent; they say I feel gassy or I've got wind. Though actually, some writers also use it in a second, bookish way, for speech that is puffed up and full of empty air — but that use is uncommon in daily talk. The condition itself is called flatulence; a person is flatulent.