Better approach to querying sqlite database in swift

I'm working on a word game and have bundled a complete list of english words using a sqlite database. I'm trying to find the best way to search the database for a given string to determine if it's a word.

At this point I can get the whole database out into an array:

func fetchWords() {
    if let managedObjectContext = (UIApplication.shared.delegate as? AppDelegate)?.managedObjectContext {

        let wordsFetch = NSFetchRequest<NSFetchRequestResult>(entityName: "EnglishWord")

        do {
            englishWords = try managedObjectContext.fetch(wordsFetch) as! [EnglishWord]

            print(englishWords[123323].word)
            //Prints "injustices"

            } catch {
                //error handling
            }
        }
    }

Now. What I really want to do is pass in a given string and see if it exists as a word in my database. I have a clunky solution with predicates, e.g:

func fetchWordsToArray() {
        if let managedObjectContext = (UIApplication.shared.delegate as? AppDelegate)?.managedObjectContext {

            let wordsFetch = NSFetchRequest<NSFetchRequestResult>(entityName: "EnglishWord")

            let searchWord = ["dastardly"]
            let searchPredicate = NSPredicate(format: "word = %@", argumentArray: searchWord)

            do {
                englishWords = try managedObjectContext.fetch(wordsFetch) as! [EnglishWord]

                let resultFilteredByPredicate = (englishWords as NSArray).filtered(using: predicate)
                print(resultFilteredByPredicate)

            } catch {
                //error handling
            }
        }

    }

But in order to use the filtered function I have to convert to an NSArray which means I can't work with the results directly (e.g. get resultFilteredByPredicate.word).

Also it feels like I'm probably going about this all the wrong way. Since everything has to go into an array first, I must be losing a lot of the value of using an sqlite database in the first place.

Any suggested approaches for better working with the database?

Many thanks in advance for any help!