stand

   1. the erect penis

   Of obvious derivation, and as a verb:

    When it stands well with him, it stands well with her. (Shakespeare, The Comedy of Errors)

   The penis may also be said to stand to attention, from the upright posture in military drill:

    She finished... posing as a nude Britannia with helmet and union jack. I wondered how many of the audience would be standing to attention. (Monkhouse, 1993)

   or be brought to attention:

    Man you should have seen that redhead bitch in the green thong. On a scale of one to ten, she's a twelve. Bring you all the way to attention. (Koontz, 1997)

   2. to be available for breeding

   Standard English of a male quadruped, although mount is more appropriate:

    ... the stallion has stood for three seasons and therefore covered a hundred and twenty mares. (D. Francis, 1982)