When you select a word using a gesture, OSX integrated dictionary opens, but the dictionary find a first word in a text line.  For example, In "This is an error." if I select 'error', then the dictionary will open for 'This'.

I observed this problem happened with Writer and Spreadsheet and did not test other applications in Libreoffice, but I expect the same problem may happen in the others. 


Note:  
I think this problem may not be a bug but may be just an unimplemented feature in Libreoffice applications. When a word selected and right click to open the context sensitive menu, "look up (dictionary)" feature is not there. 

I think it will improves the usability of Libreoffice if OSX integrated dictionary can be used in Libreoffice applications. So, if this is not bug, it should go to new feature request.