bowlder bowlder /ˈboʊldər/

noun

1. () [Non-standard] A large smooth mass of rock detached from its place of origin  ( boulder , bowlder [Non-standard] )
   a large smooth mass of rock detached from its place of origin
     The massive boulder stood as a silent sentinel, a testament to the power of ancient geological forces.
   The massive boulder stood as a silent sentinel, a testament to the power of ancient geological forces.