Green’s Dictionary of Slang

a general intensifier, usu. with derog. implications.

1514		Skelton Agenst Garnesche iii line 135: Men sey ye wyll wax lowsy, Drunken, drowpy, drowsy.
1934		H. Miller Tropic of Cancer (1963) 173: You treated me lousy just before I went away.
1948		N. Mailer Naked and Dead 6: Everything turned out lousy for him.
1950		K. Williams Diaries 4 June 53: Paris is lousy hot. I want to go back to Londres.
1979		‘Iceberg Slim’ Airtight Willie and Me 76: The track was lousy slow all night.
1989		C. Hiaasen Skin Tight 19: It went lousy [...] the ultimate fucking lousy.