home Stefano Marchionini herculean her⋅cu⋅le⋅an [hur-kyuh-lee-uhn, hur-kyoo-lee-uhn] –adjective 1. requiring the great strength of a Hercules; very hard to perform: Digging the tunnel was a herculean task. 2. having enormous strength, courage, or size. 3. (initial capital letter) of or pertaining to Hercules or his labors. h a b c d e f g h i j k l m n o p q r s t u v w x y z hair hand half heart hang hang-time heaven herculean helicopter hickey hide-and-seek hig-hz hair-dryer