WordWeb Online

1. (of a ship etc.) go under water
   "The raft went under and its occupants drowned";
   - sink, settle, go down
    
2. (astronomy) go down below the surface (esp. of water) to become submerged
   "the sun goes under early these days";
   - set, go down
    
3. Be called; go by a certain name
   "She goes under her maiden name again";
   - go by

Derived forms: going under, goes under, went under, gone under

See also: travel

Type of: come down, descend, fall, go down, sink