steamroller

Short definition from Wiktionary

Noun

1. 1
   A steam-powered heavy road roller.
2. 2
   Any heavy road roller.
3. 3
   Any seemingly irresistible force.
4. 4
   A pipe, used for smoking cannabis, open at both ends and having a bowl near one end.

Verb

1. 1
   To level a road using a steamroller.
2. 2
   To proceed ruthlessly against all opposition as if with an overwhelming force.