Word: 
Similar-sounding words in the dictionary:
4 letters:
koff
5 letters:
kafer, kifer, offer
6 letters:
caller, causer, conger, copher, coughs, haufer, keefer, keffer, keifer, kiefer, kocher, laufer, soffer, kaufer
7 letters:
coughed, keiffer, kieffer, lauffer