analog

Something that bears an analogy to something else

An organ or structure that is similar in function to one in another kind of organism but is of dissimilar evolutionary origin

A structural derivative of a parent compound that often differs from it by a single element

(of a device or system) in which the value of a data item (such as time) is represented by a continuous(ly) variable physical quantity that can be measured (such as the shadow of a sundial)