noun.
Something that bears an analogy to something else; something that is comparable.
noun.
An organ or structure that is similar in function to one in another kind of organism but is of dissimilar evolutionary origin.
noun.
A structural derivative of a parent compound that often differs from it by a single element.
adjective.
Of, relating to, or being a device in which data or a signal is represented by continuously variable, measurable, physical quantities, such as length, width, voltage, or pressure.