Get The Definition of a Word
You may not even realize that macOS includes a standalone Dictionary app that can be used to look up definitions, synonyms, and antonyms. Since this is tied deeply into the macOS and iOS operating system — you can look up a word from just about any app by right-clicking or tapping and holding and selecting “Look Up” — it’s shouldn’t be a big surprise that this is built into Spotlight as well.
To find the definition of a word, simply call up Spotlight on macOS or iOS, and type it right in. If the word is something that’s likely to appear in other search results, you may want to suffix it with “definition” to tell Spotlight what you’re looking for an ensure it appears at the top of the results, rather than below other references that Spotlight finds for that particular word.
On macOS, the Spotlight preview panel will show the full dictionary entry, and pressing return or double-clicking will open it in the Dictionary app. On iOS, you can tap on the result card to bring up the full dictionary entry, but there’s no equivalent to the Dictionary app on iOS.