yellow

The colour of gold, cheese, or a lemon; the colour obtained by mixing green and red light, or by subtracting blue from white light.

(US) The intermediate light in a set of three traffic lights, the illumination of which indicates that drivers should stop short of the intersection if it is safe to do so.

(snooker) One of the colour balls used in snooker, with a value of 2 points.

(pocket billiards) 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).

(sports) A yellow card.

Any of various pierid butterflies of the subfamily Coliadinae, especially the yellow coloured species. Compare sulphur.