USA, 1937—an uneasy sensation felt, especially in the stomach, as a result of nervousness or apprehension—based on the notion that the fluttering of butterflies may produce a similar sensation
USA, 1839—the whole group or set of people, animals or things—origin unknown—perhaps from the Dutch expression ‘de hele kit en boedel’, meaning ‘the entire house and everything in it’
USA, 1814—the whole group or set of people, animals or things—corresponds to modern Dutch ‘de hele boel’ (earlier ‘de hele boedel’)—‘boodle’: from Dutch ‘boedel’, estate, property, a large quantity
southern United States of America, 1827—used almost exclusively in the phrase ‘in cahoots’ (in early use ‘in cahoot’, ‘in cohoot’), meaning colluding or conspiring together secretly—origin unknown
UK, 1854—to belong to, or to sympathise with, two opposite groups, factions, etc.—probably a loan translation from French ‘avoir un pied dans les deux camps’ (1843)
1613—used hyperbolically of any impressive object, etc.—also applied ironically to a self-satisfied or arrogant person—refers to the seven wonders of the world, i.e., the seven most spectacular man-made structures of the ancient world
USA, 1853—in a panic-stricken and unthinking manner—alludes to the phenomenon whereby a chicken can move about for a short time after decapitation, due to reflex activity of the nervous system
USA, 1950—a midday meal, with several martinis taken as aperitifs, enjoyed by businessmen, and/or politicians, and/or federal-government employees—especially in ‘two-martini lunch’ and ‘three-martini lunch’
UK, 1710—in a situation in which any action one takes will have adverse consequences—‘cleft’, past participle of the verb ‘cleave’, means ‘split in two to a certain depth’—the image is of one being squeezed between the stick’s prongs