Affinity

Attraction between particles or substances to other particles or substances. In biological and biochemical fields, this term generally is a measure of the attraction of one biological molecule toward another molecule (which can be organic or inorganic), either to alter it, destroy it, or form a compound with it. Examples are enzymes and their substrates, or antibodies and their antigens.

From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.

Af*fin"i*ty (#), n.; pl. Affinities(#). [OF. afinit'e, F. affinit'e, L. affinites, fr. affinis. See Affined.]

1.

Relationship by marriage (as between a husband and his wife's blood relations, or between a wife and her husband's blood relations); -- in contradistinction to consanguinity, or relationship by blood; -- followed by with, to, or between.

Solomon made affinity with Pharaoh. 1 Kings iii. 1.

2.

Kinship generally; close agreement; relation; conformity; resemblance; connection; as, the affinity of sounds, of colors, or of languages.

There is a close affinity between imposture and credulity. Sir G. C. Lewis.

2.

Companionship; acquaintance.

About forty years past, I began a happy affinity with William Cranmer. Burton.

4. Chem.

That attraction which takes place, at an insensible distance, between the heterogeneous particles of bodies, and unites them to form chemical compounds; chemism; chemical or elective affinity or attraction.

5. Nat. Hist.

A relation between species or highe groups dependent on resemblance in the whole plan of structure, and indicating community of origin.

6. Spiritualism

A superior spiritual relationship or attraction held to exist sometimes between persons, esp. persons of the opposite sex; also, the man or woman who exerts such psychical or spiritual attraction.

© Webster 1913.