a mechanical system of rods or springs or pivots that transmits power or motion
(genetics) traits that tend to be inherited together as a consequence of an association between their genes; all of the genes of a given chromosome are linked (where one goes they all go)
the act of pairing a male and female for reproductive purposes; "the casual couplings of adolescents"; "the mating of some species occurs only in the spring"
a mechanical device that serves to connect the ends of adjacent objects