1. Underneath means in a lower position than something else.
The sheets are underneath the blankets on the shelf.
2. Underneath means covered by.
I found my jacket underneath the other coats.
3. Underneath indicates concealed feelings.
Underneath her smile there is a lot of heartache.
He is really very kind underneath his stern appearance.
Dolphin Push Up
Start out in dolphin pose (think down-dog with elbows on the floor). Lean forward, lowering the shoulders until the head is over the hands. Pull up the arms and return to the starting position. (No ocean necessary.)