You can create a dictionary in Babylon format and compile it with stardict-editor (see on Stardict site) or stardicttools under Linux (it is in the Ubuntu repository).
You create a plain text file in UTF-8 encoding.
The first line must be empty. The last one too.
The structure of data is show by the example below.
As you can see you can use HTML tags to format text and include pictures.
You can link to other words in the dictionary with bword.
I suppose you can also compile this file with the tool from Babylon, but I have never tried it.
See
http://www.babylon.com/support/faq/builder.html------Beginning of file----
#stripmethod=keep
#sametypesequence=h
#bookname=Best dictionary in the universe
#author=Genius Junior
#description=Dictionary with incredible definitions.
'bout <font face="Kingsoft Phonetic Plain" color="#0000ff">/baUt/</font> <i>adv, prep spoken informal</i> <br>about<br> <img src="8CB0DC57.png"><font color="#004080"><i>What are you talking 'bout?</i></font>
'em
'em <font face="Kingsoft Phonetic Plain" color="#0000ff">/Em/</font> <i>pron spoken</i> <br>sometimes used as a short form of 'them'<br> <img src="8CB0DC57.png"><font color="#004080"><i>Go on, Bill, you tell 'em!</i></font>
abad
<A href="bword://abat">abat</A>
------End odd file-----