noun The color of sunflower petals and lemons; the color obtained by mixing green and red light, or by subtracting blue from white light; the color evoked by light of wavelength around 580 nm; one of the three primary colors in subtractive color systems.
yellow:
noun The middle light in a set of three traffic lights, the lighting of which indicates that drivers should stop short of the intersection if it is safe to do so.
noun One of the color balls used in snooker, with a value of 2 points.
noun One of two groups of object balls, or a ball from that group, as used in the principally British version of pool that makes use of unnumbered balls (the yellow(s) and red(s)); contrast stripes and solids in the originally American version with numbered balls).
noun A yellow card.
noun A yellow dye or pigment.
noun A pen, pencil, crayon, etc., made of yellow pigment.
noun Something, or a part of a thing, which is yellow.