focus, foci +

A method of concentrating an electron beam by utilizing the residual gas in a tube.

Beam electrons ionize the gas molecules, forming a core of positive ions along the path of the beam which attracts beam electrons and so makes the beam more compact.

1. Pertaining to, or designating a family unit or structure headed by the mother and lacking a father permanently or for extended periods.
2. Focused or centered on the mother.

1. Having several foci.
2. With reference to an eyeglass lens having several focusing areas that correct for both nearsightedness and farsightedness.

1. A lens for near and distant vision in which the reading portion is a continuously variable curve.
2. A lens whose power increases continuously and regularly in a downward direction, avoiding the discontinuity of bifocal and trifocal lenses.

For the altar. For the hearth.

Also "For the altar (church or religion), For the hearth (home).

1. To change or to adjust the focus of something; such as, a camera or a telescope.
2. To concentrate attention or efforts on something different.

1. Changing or adjusting the focus of something; such as, a camera or a telescope.
2. Concentrating, or focusing, attention or efforts again on something different.

1. Having three focal lengths.
2. Having one section that corrects for distant vision, a second section that corrects for medium vision, and a third that corrects for near vision, as an eyeglass lens.

A lens with three parts of different refracting powers: the upper for distant, the middle for intermediate, and the lower for near vision.

1. Not adjusted for a clear image.
2. Lacking a clear purpose or objective.
3. Not centered on anything specific.