अंडरग्राउंड
Andargrāund
The word 'underground' means something that is below the ground, like tunnels or caves. It can also mean something that is not very well known or hidden.
You pronounce 'underground' like this: un-der-ground. The 'un' sounds like 'un' in 'fun', 'der' sounds like 'der' in 'derby', and 'ground' sounds like 'ground' in 'grounded'.
The word 'underground' comes from the Old English words 'under' meaning 'below' and 'grunde' meaning 'ground'. So it literally means 'below the ground'.
The word 'underground' in Hindi is 'भूमिगत' (Bhūmigat).