noun

• (programming, countable) A program that reads source code written in assembly language and produces executable machine code, possibly together with information needed by linkers, debuggers and other tools.
• (computer languages, informal, chiefly uncountable) Assembly language.
• (countable) One who assembles items.
• (nanotechnology, countable) A nanodevice capable of assembling nanodevices, possibly including copies of itself, according to a plan.