Noun

(wikipedia sensitivity) (sensitivities)

The quality of being sensitive.

The ability of an organism or organ to respond to external stimuli.

* {{quote-magazine, year=2013, month=July-August, author= Fenella Saunders, magazine=(American Scientist)

, title= Tiny Lenses See the Big Picture , passage=The single-imaging optic of the mammalian eye offers some distinct visual advantages. Such lenses can take in photons from a wide range of angles, increasing light sensitivity . They also have high spatial resolution, resolving incoming images in minute detail.}}

(statistics) The proportion of individuals in a population that will be correctly identified in a binary classification test.

(electronics) The degree of response of an instrument to a change in an input signal.

(photography) The degree of response of a film etc. to light of a specified wavelength.

Noun

(countable, and, uncountable) An ache or bodily suffering, or an instance of this; an unpleasant sensation, resulting from a derangement of functions, disease, or injury by violence; hurt.

The greatest difficulty lies in treating patients with chronic pain .

I had to stop running when I started getting pains in my feet.

(uncountable) The condition or fact of suffering or anguish especially mental, as opposed to pleasure; torment; distress; sadness; grief; solicitude; disquietude.

In the final analysis, pain is a fact of life.

The pain of departure was difficult to bear.

(countable) An annoying person or thing.

Your mother is a right pain .

(uncountable, obsolete) Suffering inflicted as punishment or penalty.

You may not leave this room on pain of death.

Interpose, on pain of my displeasure. — Dryden

We will, by way of mulct or pain , lay it upon him. — Bacon

Labour; effort; pains.