Thesaurus on Pages

When you open the Preference pane in the Apple Dictionary application, drag to organize the individual dictionaries in the order from top to bottom in that pane, as you would want to see their results listed in the output that Barry shares with you.

Also, you can invoke the Lookup word feature by hovering your pointer over a word in Pages (no need to select the word first), and then press control+command+d. Alternatively, you can three-finger tap on the trackpad after placing the pointer over a word with the same result. This has to be configured in the System Preferences : Trackpad panel beforehand.

Paragraph two will work with any word that the pointer is placed over, and not restricted to Pages, as I just did so in FireFox 78.0.2.

Control-click (or right click) on a word, then choose Look up "word" from the menu tht opens"

Then click "more" at the end of the appropriate item in this menu:

Regards,

Barry