For women? You usually don't. Most women don't ejaculate, so there isn't anything that is analogous to the "cum" or ejaculate you may have experienced when a man has an orgasm.
On the somewhat rare occasions when a woman does ejaculate fluid during orgasm, it is thinnish and watery, usually clear or whitish in color, and comes out of the urethra (same place urine comes from), but does not smell like and is not urine.
Women's other sexual fluids come out of the vagina, and aside from the amount (which is greater during arousal and sexual activity), they are usually not easily distinguished from normal vaginal self-lubrication.
One usage of the word is to mean "orgasm." Women can and do do have orgasms.
"Cum" can also mean "ejaculate," usually referring to a male orgasm. Ejaculation of semen is a very typical part (*the* typical part, to most people) of men's orgasms. Some women, sometimes, have ejaculation of fluid when they have orgasms. This fluid is not semen. See my post above for more on that.
Almost all women, however, will have an increase in vaginal fluids when they are aroused and when they are engaged in sex.
See my post above for more details on that as well. Does this clear things up at all?
Copyright 1998, 2014 Heather Corinna/Scarleteen
Scarleteen.com: Providing comprehensive sex education online to teens and young adults worldwide since 1998
Information on this site is provided for educational purposes. It is not meant to and cannot substitute for advice or care provided by an in-person medical professional. The information contained herein is not meant to be used to diagnose or treat a health problem or disease, or for prescribing any medication. You should always consult your own healthcare provider if you have a health problem or medical condition.