The act of keeping oneself in the background, as in humility.

(physics) The energy of a heterogeneous (polychromatic) photon beam calculated as if it were monochromatic

Returning a benefit that justifies the initial investment; economical.

plural of placebo effect

The act of expunging, of wiping out; expungement. / Withdrawal in order to make oneself inconspicuous; the making of oneself inconspicuous.

(medicine) The lowest pharmaceutical dosage required to cause effect in 50% of average individuals.

(physics) The increase in the wavelength, and corresponding decrease in the energy, of photons (especially of X-rays and gamma rays) when scattered by interaction with matter

Shy, extremely humble and modest; making oneself seem unnoticeable.

(quantum field theory) The effect of the Casimir force.

plural of effacement