Green’s Dictionary of Slang

boner n.4

[bone n.1 (1a)]

1. [1950s+] an erection.

2. [1980s+] the penis.

3. [1990s+] (Aus.) of a man, one who has sexual intercourse; thus mad boner, an especially keen fucker n. (1)

4. [1990s+] (Aus.) a general term of abuse, on pattern of fucker n. (3)

5. [2000s] (US) in fig. use of sense 1, an obsession.

In phrases

bounce one’s boner (v.)

[1990s+] to masturbate.

have a boner for (someone) (v.)

[2000s] to be obsessed (usu. negatively) with.