Definitions for focal point
Random House Webster's College Dictionary
either of two points on the axis of a mirror, lens, or other optical system, on which rays converge or from which they deviate.
the center of activity or attention.
the central or principal point of focus.
Origin of focal point:
focus, focal point(noun)
a point of convergence of light (or other radiation) or a point from which it diverges
focus, focal point, nidus(noun)
a central point or locus of an infection in an organism
"the focus of infection"
focus, focusing, focussing, focal point, direction, centering(noun)
the concentration of attention or energy on something
"the focus of activity shifted to molecular biology"; "he had no direction in his life"
A focus; a point at which rays of light or other radiation converge
The centre of any activity
A feature that attracts particular attention.