analogue (noun): in organic chemistry, a compound that is structurally similar to another (structural analogue) or performs the same functions (functional analogue); in biology, an organ or part with a different origin but the same function (eg the wings of a bee and the wings of a bird)

analogous (adjective): in evolutionary biology, referring to organs that have the same function or are similar in appearance but are not equivalent morphologically and did not evolve from the same organs (eg the wings of a bee and the wings of a bird)

analog (adjective): referring to information that is not digital, or a device that records information in a way that is not digital (ie properties are encoded in terms of frequencies and their amplitudes)

homologue (noun), homologous (adjective): in evolutionary biology, refers to things that have the same structure and origin but not necessarily the same function or appearance (eg the wing of a bird and the foreleg of a horse). In genetics, describes a pair of chromosomes (one from the mother and one from the father) that have the same genes at the same loci. In molecular biology, describes sequences (DNA or protein) with a shared ancestry. In chemistry, describes a series of organic compounds of the same chemical type, but differing by a fixed increment in a repeating unit, or chemical elements that occur in the same group of the periodic table and share some electrochemical properties. In medicine, relates to an antiserum in which the antibodies correspond to the antigenic material that was used to produce the antiserum. Also sometimes used in developmental psychology to indicate behaviours that have common origins

homeologue: in molecular biology, homeologous chromosomes are chromosomes from different species that are partly similar as a result of a common ancestor (ie only partly homologous)