Green’s Dictionary of Slang

(US) very loose, in any sense.

1930		D.M. Garrison ‘Song of the Pipeline’ in Botkin Folk-Say 106: There, she’s loose as a goose. Jack. Roll.
1953		Randolph & Wilson Down in the Holler 178: Loose as a goose refers to diarrhea.
1961		S. Paige in Sat. Eve. Post 11 Mar. 38: The Indians’d won seven in a row and had three straight shutouts. With that kind of luck, any player should be goose loose.
1966		‘Tom Pendleton’ Iron Orchard (1967) 127: I been loose as a goose all week.
1969		Time 27 June n.p.: He is long off the tee, and he uses an unorthodox, cross-handed style for putts because ‘I’m too loosey-goosey, doing it the regular way.’.
1978		R. De Christoforo Grease 158: We were loose as a caboose, mostly from the punch.
1979		E. Torres After Hours 23: I’m lookin’ like money [....] casual, loosey-goosey.
1985		J. Wambaugh Secrets of Harry Bright (1986) 150: I wanna see you loosey goosey up there on the eighteenth tee.
1998		(con. 1960s) G. Washington Blood Brothers 11: ‘You want some cocaine to get a little loose, or some magic mushrooms?’ I knew he had some just for this party and they were from Mexico, beautiful stuff it was and made you feel loose like a long necked goose.
2000		Guardian 16 Feb. 18: Loose as a goose I was, if you’ll pardon my anatomicals!
2001		‘Randy Everhard’ Tattoo of a Naked Lady 236: He gesticulated too, all loosey-goosey.
2019		S.M. Jones Lives Laid Away [ebook] ‘ICE records of detentions and arrests have always been loosey-goosey [...] Strong on the enforcement side, weak on the administrative side’.
2021		J. Ellroy Widespread Panic 163: I spike-speared her [i.e. with truth serum] and she went loosey-goosey.