WordWeb Online

1. The process of forming metal into sheets by passing it between rolls
   - flatting

1. Make flat or flatter
   "flatten your stomach with these exercises";
   - pancake
    
2. Become flat or flatter
   "The landscape flattened";
   - flatten out, pancake
    
3. (music) lower the pitch of (musical notes)
   - drop
    
4. Destroy (a building or buildings) so as to make nearly level the ground
   - level, raze, rase, dismantle, tear down, take down, pull down

Derived forms: flattenings

Type of: alter, change, change form, change shape, deform, destroy, destruct, form, modify, shape, spifflicate [Brit, informal], spiflicate [Brit, informal], uncreate [literary]

Encyclopedia: Flattening