ID has no import filters for that format. Can you convert it to something like RTF?
Im trying, but lexique pro keeps crashing, probably due to file size. Attempting a docx format, then maybe I'll try manually splitting the file into several parts to ease exporting.
I've not worked on a dictionary for which the terms were stored in an XML format in a few years. However, in one case, we could tweak the XML output at the database-export stage (easy) and in another we were able to use XSL transforms to bash the XML into an easily-imported form (not as easy).
Neither one was in LIFT format, and after eyeballing the spec I think that I'd encourage you to think about XML import. Much depends on how eager you are to learn how to use InDesign's XML-import tools. Which, TBQH, are not great if your XML data are anything other than Perfectly Clean, unless you happen to already have a background in massaging XML into shape with XSL. Which I've done a few times now, with varying degrees of success and new white-hair generation.
Joel's comments made me curious. So I downloaded and looked at the export to .LIFT. Make a copy of the LIFT file and change the extension to XML. It is well formed, if not verbose, XML.
Depending upon how much you need to manipulate it, the editing requirements can range from a good text editor or an XML editor for "simple" search and replaces (removing lines, etc.) to full-blown XSLT work.