Touching a person's sex organs for pleasure. This could be a male rubbing his penis or a female rubbing her clitoris because it feels good. People can do it alone or with another person. Masturba [..]

1711 (earlier as mastupration, 1620s), from French masturbation and directly from Modern Latin masturbationem (nominative masturbatio), noun of action from past participle stem of Latin masturbari &qu [..]

Jewish law strictly prohibits male masturbation. Female masturbation is a matter of less clarity, but it is also frowned upon.

is the process of manipulating ones own genital organs, whether a penis or clitoris for the purposes of self-stimulating removing the requirement for a partner.

(n) manual stimulation of the genital organs (of yourself or another) for sexual pleasure

  Self stimulation of the genitals for erotic pleasure.

Sexual self-stimulation.

Sexual self-stimulation.

Manual production of vicious excitement (19thC)

Refers to sexual stimulation other than through sexual intercourse (e.g. using hands), and particularly sexual self stimulation.

Sexual stimulation or gratification of the self.

Sexual stimulation or gratification of the self.

From the Latin words manstuprare, from manus "hand" (as in manual) + stuprare "defile" (oneself), from stuprum "defilement, dishonor," related to stupere "to be stunned, stupefied" (as in stupid).

Massaging one's own genitals, usually to the point of orgasm.

masturbation

Self-stimulation of your own genitals and body, for sexual pleasure or orgasm.

Erotic stimulation of one's own genitals to achieve orgasm

sexuoerotic genital self-stimulation by pressure or touch, self-stimulation, usually though not necessarily climaxing in orgasm [from Latin, manus, hand + st[u]parare, to deflower, ravish, fornicate, [..]

Touching one’s own body and sex organs for sexual pleasure.