b (1): an attraction to or liking for something <people with an affinity to darkness — Mark Twain><pork and fennel have a natural affinity for each other — Abby Mandel>(2): an attractive force between substances or particles that causes them to enter into and remain in chemical combination
c: a person especially of the opposite sex having a particular attraction for one
a: likeness based on relationship or causal connection <found an affinity between the teller of a tale and the craftsman — Mary McCarthy><this investigation, with affinities to a case history, a psychoanalysis, a detective story — Oliver Sacks>
b: a relation between biological groups involving resemblance in structural plan and indicating a common origin
See affinity defined for English-language learners
He never felt any affinity with the other kids in his neighborhood.
Jefferson's personal debts continued to mount … . His addiction to French wine, like his affinity for French ideas, never came to grips with the more mundane realities. —Joseph J. Ellis, American Heritage, May/June 1993
… neither virus has an affinity for T cells. —Robert C. Gallo, Scientific American, 1987
Animals sharing this basic architecture may have no closer affinity than a beetle and a squid. —Stephen Jay Gould, Natural History, 1985
attraction, affinity, sympathy mean the relationship existing between things or persons that are naturally or involuntarily drawn together. attraction implies the possession by one thing of a quality that pulls another to it <felt an attraction to danger>. affinity implies a susceptibility or predisposition on the part of the one drawn <an affinity for mathematics>. sympathy implies a reciprocal or natural relation between two things that are both susceptible to the same influence <two minds in sympathy>.