Underground fortification that defends against bombs and other attacks

Answer of Word Craze Underground fortification that defends against bombs and other attacks

This is a tricky question of Word Craze which last appeared on Level 86. Meanings or answers can change from time to time with each game update if you noticed a change on the answer of this clue please do let us know by commenting below so we can fix it A.S.A.P.
The solution below is:

For other clue answers of Level 86 Word Craze Level 86 Answer open the the level link.