> Lastly, double clicking with three fingers on a selected word in any standard app now brings up the inline dictionary, which formerly required selecting “Look Up In Dictionary” from the contextual menu. A preference setting within Dictionary selects whether the contextual menu command will open the inline mini-dictionary panel or to launch the full Dictionary app.
What I usually do are :
Launch Dictionary.app via Alfred → Type the word then press enter → Press cmd + H to hide the program
This save a lot of time.