noun Any plant of the family Poaceae, characterized by leaves that arise from nodes in the stem and leaf bases that wrap around the stem, especially those grown as ground cover rather than for grain.
noun Any of the various plants that are not in the family Poaceae that resemble grasses.
noun A lawn.
noun The outside world, especially in the phrase "touch grass".
noun Marijuana.
noun An informer; snitch, police informer; one who betrays a group (of criminals, etc) to the authorities.
What just happened must remain secret. Don't be a grass.
noun Sharp, closely spaced discontinuities in the trace of a cathode-ray tube, produced by random interference.
noun Noise on an A-scope or similar type of radar display.