: 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
: 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
: the manner in which atoms or radicals are connected by chemical bonds in a molecule
: the relationship between genes on the same chromosome that causes them to be inherited together—compare mendel's law 2
In mechanical engineering, a system of solid, usually metallic, links (bars) connected to two or more other links by pin joints (hinges), sliding joints, or ball-and-socket joints to form a closed chain or a series of closed chains. When one link is fixed, the possible movements of the other links relative to the fixed link and to one another depend on the number of links and the number and types of joints. With four pin-connected links, for example, the links all move in parallel planes, and regardless of which link is fixed, the others move in a fixed way relative to the fixed link. With various relative lengths of the links, this four-bar linkage becomes a useful mechanism for converting uniform rotary to non-uniform rotary motion or continuous rotary to oscillatory motion. It is the most commonly used linkage mechanism in machine construction.