[Greek makros, long, large.]
This combining form is widely distributed, especially in scientific and technical contexts. The macrocosm (Greek kosmos, world) is the universe or the whole cosmos; a macromolecule contains a very large number of atoms, such as a protein, nucleic acid, or synthetic polymer; macrophotography produces photographs of small items larger than life size; macroevolution is major evolutionary change. Macro can appear as a free-standing word, as in macro lens, one used in macrophotography, or as an abbreviation of the computer term macro instruction, a single instruction that expands into a set to perform a given task. Also related is macron, a written or printed mark (̄) used to indicate a long vowel or a stressed vowel in verse. Macro- is often contrasted with micro-.