The term BUSILY EMPLOY is composed of four words: PLIED, PLY, HUM, and PLIES. PLIED is a verb meaning to twist or braid together, while PLY is a verb meaning to work diligently. HUM is a verb meaning to make a low, continuous sound, and PLIES is a verb meaning to use or apply something. Together, these words describe someone who is working diligently, twisting and braiding together, and using or applying something while making a low, continuous sound.