Green’s Dictionary of Slang

1. courage.

1960		J. Franklyn Dict. of Rhy. Sl.
1978		Maledicta II:1+2 (Summer/Winter) 118: Elsewhere Aylwin lists a few more ‘Vulgarities’: [...] spunk (Maria Monk, spunk meaning courage as in US ‘full of spunk’ but equivalent to sperm or cum in some British circles).

2. semen.

1960		J. Franklyn Dict. of Rhy. Sl.
1972		B. Rodgers Queens’ Vernacular 53: semen [...] maria (Brit gay sl: ‘Maria’s on your tweeds, dear’).
1978		see sense 1.
1998		B. Robinson Peculiar Memories of Thomas Penman 8: Maris = Sperm (Maria Monk/Spunk).
2019		P. Baker Fabulosa 294/2: Maria sperm.