CUE: The "cue" is a stage direction which tells an actor when to walk on stage. It was originally the letter Q, an abbreviation of the Latin word
quando, meaning "when." So the cue (Q) indicated when an actor was to come on the stage. The word "cue" can now mean a sign about when to speak or act, any kind of a hint, a guiding suggestion, etc.
QUEUE: English "queue" is from French queue, ultimately from Latin
cauda, meaning "tail." In English "queue" can be used to mean a plait of hair (compare "ponytail"), and it can also refer to a line of people waiting. From this noun, we get the verb "to queue," meaning to stand in line.
