activity

[ak-tiv-i-tee] /ækˈtɪv ɪ ti/
noun, plural activities.
1.
the state or quality of being active:
There was not much activity in the stock market today. He doesn't have enough physical activity in his life.
2.
a specific deed, action, function, or sphere of action:
social activities.
3.
work, especially in elementary grades at school, that involves direct experience by the student rather than textbook study.
4.
energetic activity; animation; liveliness.
5.
a use of energy or force; an active movement or operation.
6.
normal mental or bodily power, function, or process.
7.
Physical Chemistry. the capacity of a substance to react, corrected for the loss of reactivity due to the interaction of its constituents.
8.
Physics.
  1. the number of atoms of a radioactive substance that disintegrate per unit of time, usually expressed in curies.
  2. radioactivity.
9.
an organizational unit or the function it performs.
Origin
1520-30; (< Middle French) < Medieval Latin āctīvitās. See active, -ity
Related forms
nonactivity, noun, plural nonactivities.
preactivity, noun, plural preactivities.
superactivity, noun, plural superactivities.
Examples from the web for activity
  • Of course, the state's activity has been vast and important.
  • On the other, weak housing investment and high interest rates are likely to have restrained consumer activity.
  • The epithelium of the mamma differs according to the state of activity of the organ.
  • Based on their answers, they were put into five groups of varying activity levels from inactive to highly active.
  • They also pointed out that it's unlikely heat from the active phones was to blame for the changes in brain activity.
  • For the new study, researchers created special mice whose telomerase activity could be switched on and off.
  • Mergers and acquisitions activity continues to languish this year as the fallout from the economic crisis lingers.
  • The basis of her firing has to be other than alleged criminal activity.
  • Since then, however, there has been little activity.
  • Click for more great links related to this activity.
British Dictionary definitions for activity

activity

/ækˈtɪvɪtɪ/
noun (pl) -ties
1.
the state or quality of being active
2.
lively action or movement
3.
any specific deed, action, pursuit, etc: recreational activities
4.
the number of disintegrations of a radioactive substance in a given unit of time, usually expressed in curies or disintegrations per second
5.
  1. the capacity of a substance to undergo chemical change
  2. the effective concentration of a substance in a chemical system. The absolute activity of a substance B, λB, is defined as exp (μBRT) where μB is the chemical potential
Word Origin and History for activity
n.

c.1400, "active or secular life," from Old French activité, from Medieval Latin activitatem (nominative activitas), a word in Scholastic philosophy, from Latin activus (see active). Meaning "state of being active, briskness, liveliness" recorded from 1520s; that of "capacity for acting on matter" is from 1540s.

activity in Medicine

activity ac·tiv·i·ty (āk-tĭv'ĭ-tē)
n.

  1. A physiological process.

  2. The presence of neurogenic electrical energy in electroencephalography..

  3. An ideal concentration for which the law of mass action will apply perfectly.

  4. The intensity of a radioactive source.

  5. The ability to take part in a chemical reaction.