Large round bottom, hard to ignore in yoga position (5)
I believe the answer is:
lotus
'yoga position' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for lotus that I've seen before include "Sacred waterlily" , "In Greek mythology, a fruit which induces forgetfulness" , "Sacred Egyptian water lily" , "Tropical water-lily" , "TREE" .)