In fact I already found the solution, this post is to help users in the same case.
When Lingo 3.0 is installed with Semantic MediaWiki, the definition are not displayed (…properly, because they are displayed at the end of the page if you can see this part). This was a name conflict for the ResourceLoader module called ext.jquery.qtip already used by Semantic MediaWiki. This was fixed in Lingo by Stephan on 9 September 2019, and published in Lingo 3.1.0.
So it can be fixed by upgrading Lingo to 3.1.0 (or newer).