Mach-O, short for Mach object file format, is a file format for executables, object code, shared libraries, dynamically-loaded code, and core dumps. A replacement for the a.out format, Mach-O offers more extensibility and faster access to information in the symbol table.

Machismo (; (from Spanish "macho", male); ) is the sense of being manly, the concept associated with "a strong sense of masculine pride...[with] the supreme valuation of characteristics culturally associated with the masculine and by implication some say, a denigration of characteristics associated with the feminine." It is associated with "a man’s responsibility to provide for, protect, and defend his family." In revisionist American political usage, William Safire says it refers to the "condescension of the swaggering male; the trappings of manliness used to dominate women and keep them 'in their place.'"

Massive astrophysical compact halo object (MACHO) is any kind of astronomical body that might explain the apparent presence of dark matter in galaxy halos. A MACHO is a body composed of normal baryonic matter that emits little or no radiation and drifts through interstellar space unassociated with any planetary system. Since MACHOs are not luminous, they are hard to detect. MACHOs include black holes or neutron stars as well as brown dwarfs and unassociated planets. White dwarfs and very faint red dwarfs have also been proposed as candidate MACHOs. The term was coined by astrophysicist Kim Griest.