ordNet 
in the corresponding part of speech.  On each line, following the word, 
is a list of byte offsets (<I>synset_offset </I>s) in the corresponding data 
file, one for each synset containing the word. Words in the index file 
are in lower case only, regardless of how they were entered in the lexicographer 
files.  This folds various orthographic representations of the word into 
one line enabling database searches to be case insensitive.  See <B><A HREF="wninput.htm">wninput</B>(5WN)</A>
 
for a detail