I keep the Apple Dictionary application in my Dock, dead center for ease of access.
How you order the dictionaries in its application settings will determine the left-to-right order on the Dictionary toolbar. That ordering is also relevant for the top-to-bottom presentation of dictionary results from the optional trackpad three-finger tap, or by pressing the control+command+D keyboard shortcut with the mouse pointer over the word you want to look up. One does not need to select that word, only hover over it.
And, current versions of Safari, Firefox, and Brave can open the Dictionary application by using this URI, where the word is that which is to be found in the Dictionary application, once you agree to the browser prompt to open it.
dict://word
I never use Spotlight other than to find files/folders or features on my Mac or quick calculations. Entering a word as though to look it up in a dictionary is misleading as it is telling Spotlight to scan every one of its Search Result categories for that string — including document contents.