How do I access the built-in dictionaries on iOS without hitting "Define..."?

Right now, when I need to check a word in the dictionary, I open Notes, type in something, select the word and hit "Define..."

I'd like to directly type in a word and check something, similar to how I can just type stuff into Spotlight & look up definitions in OS X.

How do I do this?

This is an old thread, but I think it's worth noting that Spotlight on iOS 11 has a built-in dictionary widget - you can type in any word and scroll down to see the dictionary. And Spotlight itself is accesible from any Home screen page.

This is currently not possible. Apple also forbids third party developers to create a simple wrapper around the dictionary, which means that there will probably not be any applications that do just that. There are, however, several other third party dictionaries which are quite good.

A UIReferenceLibraryViewController object provides a dictionary service to look up the definition of a word or term from within an app. It should not be used to display wordlists, create a standalone dictionary app, or republish the content in any form.

According to this answer Can iOS' builtin dictionary be accessed/browsed as an independent app? you can download the application DictionaryPlusPlus, which does just that, here https://github.com/josh-/DictionaryPlusPlus, it is open source and you will have to compile and sign it yourself.