Search Result for "louden": 
Wordnet 3.0

VERB (2)

1. become louder;
- Example: "The room loudened considerably"

2. cause to become loud;


WordNet (r) 3.0 (2006):

louden v 1: become louder; "The room loudened considerably" [ant: hush, pipe down, quiesce, quiet, quiet down, quieten] 2: cause to become loud [ant: hush, hush up, quieten, shut up, silence, still]