activity has definitions from the fields of physics,biology,chemistry
[ noun ] any specific activity or pursuit


"they avoided all recreational activity"

Used in print

(Richard I. McCosh, "Recreation Site Selection"...)

A site which overlooks a harbor or river may offer interest in the activities of boating traffic .

This follows naturally since frontage on an ocean , stream , or lake provides scenic values and opportunities for the very popular recreation activities of bathing , fishing , boating , and other water_sports .

(Bonnie Prudden, "The Dancer and the Gymnast"...)

Even if gymnastics are not the ultimate goal , the good tumbler will be a better dancer , a better athlete , and a human_being with a greater margin of safety in any activity .

(Jack Kaplan, "The Health Machine Menace: Therapy by...)

By preying on the sick , by playing callously on the hopes of the desperate , by causing the sufferer to delay proper medical_care , these medical ghouls create pain and misery by their very activity .

(Handbook of Federal Aids to Communities. U.S. Dep...)

One-day conferences covering some specific phase of business management , also part of the continuing activities of the Small_Business_Administration , aid community economic development programs .

[ noun ] the state of being active


action activeness


"his sphere of activity" "he is out of action"

Used in print

(Frank Oppenheimer, "Science and Fear-- A Discussion...)

Solar activities could presumably bring long periods of flood or drought .

(Francis J. Johnston and John E. Willard, "The...)

The fraction of exchange was determined as the ratio of the counts / minute observed in the carbon_tetrachloride to the counts / minute calculated for the carbon_tetrachloride fractions for equilibrium distribution of the activity between the chlorine and carbon_tetrachloride , empirically determined correction being made for the difference in counting efficiency of * * f in * * f and * * f .

(M. Yokoyama et al., "Chemical and serological...)

Anti - A and anti - B activities were determined in fractions from the sera of group A , group B or group O donors by the following tube agglutination methods .

The small amount of insoluble material which precipitated during dialysis was suspended in approximately 5 ml of starting_buffer , centrifuged , resuspended in 2.5 ml of isotonic saline and tested for antibody activity .

These were read at 280 m � m in a Beckman model DU spectrophotometer and tested for antibody activity as described above .

[ noun ] (biology) an organic process that takes place in the body


"respiratory activity"

Used in print

(Jacob Robbins et al., "The thyroid-stimulating...)

A study of their activity on thyroglobulin has shown that thyroxine is not preferentially released and that the degradation proceeds stepwise with the formation of macromolecular intermediates ( Alpers , Petermann and Rall , 1956 ) .

A microsomal de-iodinase with a pH optimum of around 8 , and requiring reduced triphosphopyridine_nucleotide for activity , has been identified in the thyroid ( Stanbury , 1957 ) .

On_the_other_hand , there are a_few antithyroid drugs of this same general type , such as resorcinol , possessing no reducing activity and possibly acting through formation of a complex with molecular iodine .

Besides the presence of goitrogens in the diet , the level of iodine itself in the diet plays a major role in governing the activity of the thyroid_gland .

In the experimental animal and in man gross deficiency in dietary iodine causes thyroid hyperplasia , hypertrophy and increased thyroid activity ( Money , Rall and Rawson , 1952 ; Stanbury , Brownell , Riggs , Perinetti , Itoiz , and Del_Castillo , 1954 ) .

[ noun ] (chemistry) the capacity of a substance to take part in a chemical reaction


"catalytic activity"

Related terms

capability chemistry

[ noun ] (physics) the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay
[ noun ] the trait of being active; moving or acting rapidly and energetically




"the level of activity declines with age"