1: the manner or style of being united: as a: the manner in which atoms or radicals are linked in a molecule b:bond 3c 2: the quality or state of being linked; especially: the relationship between genes on the same chromosome that causes them to be inherited together — compare mendel's law 2 3: a system of links; especially: a system of links or bars which are jointed together and more or less constrained by having a link or links fixed and by means of which straight or nearly straight lines or other point paths may be traced 4:link 2b 5: the tactic in diplomatic negotiations of linking often unrelated issues so that progress in one area is dependent on agreement in another