Siesta and Sandman

Siesta noun - A short sleep.

Sandman and siesta are semantically related In some cases you can use "Sandman" instead a noun "Siesta".

Sandman noun - An elf in fairy stories who sprinkles sand in children's eyes to make them sleepy.

Siesta and sandman are semantically related in sleep topic. Sometimes you can use "Siesta" instead a noun "Sandman", if it concerns topics such as suspension of consciousness.