Green’s Dictionary of Slang

1. a working man, an ‘average joe’.

1914

Ade Ade’s Fables 19: Every downtrodden Mokus owing $800 on a $500 House is honing for a Chance to Hand it to somebody wearing a Seal-Skin Overcoat.

2. (also mokers) a depressed state, ‘the blues’.

[1789		Both Sides of the Gutter part II 10: Den your souls to the gallows! when I fobb’d my mocus’s].
1928		H. Brackbill ‘Midshipman Jargon’ in AS III:6 453: Mokus — Loneliness.
1944		P. Kendall Dict. Service Sl. n.p.: I’ve got the mokers . . . the blues; depressed.

3. a very intoxicated state.

1960, 1975

Wentworth & Flexner DAS.