Green’s Dictionary of Slang

1. the penis.

1890–1904		Farmer & Henley Sl. and Its Analogues.
2000		M. Manning Get Your Cock Out 36: Pushing her over the unflushed bog and jamming his super erotic piledriver up her teenage sphinc.

2. (US tramp) strong coffee.

1930

‘Dean Stiff’ Milk and Honey Route 211: Pile driver or java – Coffee, but good strong coffee.

3. a male homosexual [play on SE piles].

1972		B. Rodgers Queens’ Vernacular 90: men who fuck hard and fast [...] pile-driver.
1992		Bentley & Corbett Prison Sl. 60: Pile Driver A person who takes the dominant role in a homosexual relationship.