Bikini

a bikini

guide, lead someone / provide guidance or useful information / provide a basic explanation, break down a topic

a guide, a leader who shows the way / guidance, providing basic instruction or helpful information / a guide who instructs / a guidebook, handbook, or manual

(uncommon) beautiful skin

a beautiful woman

(astronomy) Microscopium

an organism; a life form

to use one's head

use one thing for many purposes / work someone hard