When u eff something up but... children are around

Female masturbation. Clitoral stimulation.

a version of fuck- without having to swear

b. To masturbate.
1598 J. Florio Worlde of Wordes, Fricciare, to frig, to wriggle, to tickle.
1680 Earl of Rochester et al. Poems 14 Poor pensive Lover, in this place, Would Frigg upon his Mothers Face.
1680 Oldham in Rochester's Poems (1950) 131 There Punk, perhaps, may thy brave works rehearse, Frigging the senseless thing, with Hand, and Verse.
c1680 Sodom IV. 120, I caught one frigging with a curs bob tayle.
a1749 A. Robertson Poems (?1751) 83 So to a House of Office‥A School-Boy does repair, To‥fr— his P—— there.
1858 H. Silver Diary 21 Oct. in G. Ray Thackeray (1955) I. 452 Thackeray says one of the first orders he recḍat Charterhouse was ‘Come & frig me’.
1865 E. Sellon New Epicurean (1875) 11, I frigged and kissed their fragrant cunnies.
1865 E. Sellon New Epicurean (1875) 22 The next minute I had flung her back on the hay, and was frigging away at her maidenhead.
c1890 My Secret Life II. 268, I have frigged myself in the streets before entering my house, sooner than fuck her.
c1890 My Secret Life II. 268, I got up,‥frigged my prick, probed her.
a1935 T. E. Lawrence Mint (1955) ii. x. 128 ‘If you ask me, Sir,’ replied Taffy unabashed ‘like a pack of skeletons frigging on a tin roof.’
1946 M. Mezzrow & B. Wolfe Really the Blues 380 High-pressure romancing (find 'em, fool 'em, frig 'em and forget 'em).

not to fuck, but to insert fingers in vagina and provide pleasure by rubbing and usually finding the clit to masterbate for her.
see finger

Rubbing of any kind for sexual pleasure; masturbation, of oneself or another. Probably from Latin frico (rub) or frictio (rubbing). Also used as a semi-euphemism for _fuck_ by itself or in phrases. Usually derogatory or contemptuous.

(Term used by engineers) To make a rough-and-ready, quick-and-dirty adjustment to something to make it work or to make it operate in a particular way. To adjust manually for a particular purpose. Can be used of a physical device but also of a computer program, etc.