Look up words on Mac
You can quickly look up the definitions of words and phrases while working in apps or browsing webpages.
In an app or on a webpage on your Mac, Control-click a word or phrase (in some apps you may need to select it first), then choose Look Up from the shortcut menu.
Or you can tap the trackpad with three fingers (if the gesture is selected in Trackpad preferences). If your trackpad supports force click, you can set the Look Up gesture to use that instead of a tap.
In the Look Up window, do any of the following:
See the full definition: Click the “more” link at the end of the short definition.
See the word in the Dictionary app: Click Open in Dictionary.
See more information: Click a category — such as Knowledge or Movies — at the bottom of the Look Up window, or swipe left or right on the trackpad.
Change dictionary sources: Click Configure Dictionaries to open the Dictionary preferences window. Select or unselect sources. You can set options for a selected source, such as how to display pronunciations or which language of Wikipedia to search.
Tip: When you enable Spotlight Suggestions, some apps — for example, Mail, Messages, and Notes — may outline an item (such as an artist name, a place, or a movie title) in text or make it a link as a hint that more information is available. Just click the arrow or the link to read more in the Look Up window. (Your messages, emails and other content are not sent to Apple; only the items identified as Look Up hints and related usage data may be sent.)