Part 238

Foam cock, in steam boilers, a cock at the water level, to blow off impurities.

Foam, v. i. [imp. & p. p. Foamed (fmd); p. pr. & vb. n. Foaming.] [AS. f?man. See Foam, n.] 1. To gather foam; to froth; as, the billows foam.

He foameth, and gnasheth with his teeth.

Mark ix. 18.

2. To form foam, or become filled with foam; -- said of a steam boiler when the water is unduly agitated and frothy, as because of chemical action.

Foam, v. t. To cause to foam; as, to foam the goblet; also (with out), to throw out with rage or violence, as foam. "Foaming out their own shame." Jude 13.

Foam"ing*ly (?), adv. With foam; frothily.

Foam"less, a. Having no foam.

Foam"y (-), a. Covered with foam; frothy; spumy.

Behold how high the foamy billows ride!

Dryden.

Fob (fb), n. [Cf. Prov. G. fuppe pocket.] A little pocket for a watch.

Fob chain, a short watch chain worn with a watch carried in the fob.

Fob (?), v. t. [imp. & p. p. Fobbed (#); p. pr. & vb. n. Fobbing.] [Cf.Fop.]

1. To beat; to maul. [Obs.]

2. To cheat; to trick; to impose on. Shak.

To fob off, to shift off by an artifice; to put aside; to delude with a trick."A conspiracy of bishops could prostrate and fob off the right of the people." Milton.

Fo"cal (?), a. [Cf. F. focal. See Focus.] Belonging to,or concerning, a focus; as, a focal point.

Focal distance, or length, of a lens or mirror (Opt.), the distance of the focus from the surface of the lens or mirror, or more exactly, in the case of a lens, from its optical center. --Focal distance of a telescope, the distance of the image of an object from the object glass.

Fo`cal*i*za"tion (?), n. The act of focalizing or bringing to a focus, or the state of being focalized.

Fo"cal*ize (?), v. t. [imp. & p. p. Focalized (?); p. pr. & vb. n. Focalizing (?).] To bring to a focus; to focus; to concentrate.

Light is focalized in the eye, sound in the ear.

De Quincey.

Foc"il*late (?), v. t. [L. focilatus, p. p. of focillare.] To nourish. [Obs.] Blount.

Foc`il*la"tion (?), n. Comfort; support. [Obs.]

Fo*cim"e*ter (?), n. [Focus + -meter.] (Photog.) An assisting instrument for focusing an object in or before a camera. Knight.

Fo"cus (?), n.; pl. E. Focuses (#), L. Foci (#). [L. focus hearth, fireplace; perh. akin to E. bake. Cf. Curfew, Fuel, Fusil the firearm.] 1. (Opt.) A point in which the rays of light meet, after being reflected or refracted, and at which the image is formed; as, the focus of a lens or mirror.

2. (Geom.) A point so related to a conic section and certain straight line called the directrix that the ratio of the distance between any point of the curve and the focus to the distance of the same point from the directrix is constant.