linac vs atom smasher

linac and atom smasher both are nouns.

Word	Noun	Adjective	Verb	Adverb
linac	Yes	No	No	No
atom smasher	Yes	No	No	No

As nouns, atom smasher is a hypernym of linac; that is, atom smasher is a word with a broader meaning than linac:

linac: ions are accelerated along a linear path by voltage differences on electrodes along the path
atom smasher: a scientific instrument that increases the kinetic energy of charged particles

Other hypernyms of linac include accelerator, particle accelerator.

linac (noun)	atom smasher (noun)
ions are accelerated along a linear path by voltage differences on electrodes along the path	a scientific instrument that increases the kinetic energy of charged particles