Green’s Dictionary of Slang

(US) Los Angeles.

1913		L. Light Modern Hobo 58: Arrived at ‘Los’ in the early part of the evening.
1925		G.H. Mullin Adventures of a Scholar Tramp 125: I quit and went to Los.
1925		J. Tully Beggars of Life 237: The car’s red-tagged for Los Angels.
1931		Irwin Amer. Tramp and Und. Sl. 123: Los.—Los Angeles, Cal.
1948		(con. 1910s) J. Stevens Big Jim Turner 118: Their talk was mainly lying brags on all the vile items of life in cities they called Chi, Cincy, K.C., Los and Frisco.
2003		David Muñoz East L.A. Rifa 🌐 You’ve landed on a website by a vato from East Los – the best part of Los Angeles.