AFAIK, you cannot create Kindle lookup dictionaries with Calibre. You'll need to use Mobipocket Creator or KindleGen instead, because Kindle dictionaries require a special non-standard .html format and special non-standard .opf entries.
Here's an example of a very simple English-German dictionary with inflections.
Code:
<html>
<body>
<idx:entry>
<b><idx:orth>book
<idx:infl>
<idx:iform value="books"/>
</idx:infl>
</idx:orth> </b>
<i>Subst.</i> <br/>
Buch (n)
</idx:entry>
<br/><br/>
<hr/>
<idx:entry>
<b><idx:orth>go
<idx:infl>
<idx:iform value="goes"/>
<idx:iform value="going"/>
<idx:iform value="went"/>
<idx:iform value="gone"/>
</idx:infl>
</idx:orth> </b>
<i>Verb</i> <br/>
gehen
</idx:entry>
<br/><br/>
</body>
</html>
For more information, see the
mobipocket.com web site. If your source data is tab-delimited, you can use the instructions on this
web site to automatically generate the source files for your dictionary.