Green’s Dictionary of Slang

weenie n.1

also weener, weeny, weiner, weinie, wiener, wienie, winnie
[SAmE wiener, a Vienna sausage; ult. Ger. Wiener (Wurst)]
(US)

1. [late 19C+] (US) a frankfurter sausage; a hot dog n.1 (1); also attrib.

2. [1900s] (US Und.) bread.

3. [1920s+] (US) a young woman, an effeminate man; also attrib.

4. [1930s+] (US, usu. juv., also wennie) the penis; also attrib.

5. [1950s+] (US) a general derog. term of abuse, usu. of a male, esp. one who is socially awkard or too hard-working.

In compounds

weenie bin (n.)

[1970s+] (US campus) a library carrel.

weenie waver (n.) (also weenie wagger, ...wiggler, weinie..., wienie...)

[1970s+] an exhibitionist; also attrib.

weenie woman (n.)

[1990s+] (US) an effeminate homosexual.

In phrases

bite the weenie (v.) (also eat the weenie)

[1950s+] (US) a general derog. expression.

dip the weenie (v.) (also dip the weinie)

[1950s+] (US) of a man, to have sexual intercourse.

hide the weenie (v.)

[1910s+] to have sexual intercourse.

weenie out (v.) (also wienie out)

to surrender, to act in a cowardly manner.