Can I add to custom dictionary on the fly?

You may have to build this database based on your need and experience while typing or dictating.

Using Dictionaries in Shortcuts on iPhone or iPad

In addition to APIs, dictionaries can also be a useful way to work with structured data in your shortcuts. Use dictionaries in the following ways:

• Enter text, numbers, values, dictionaries or lists into a Dictionary action to manually create a dictionary for use in your shortcuts.
• Use the Get Dictionary from Input action to turn text containing JSON or .plist data into a dictionary item.
• Create a JSON dictionary without coding it manually by entering all the values into a Dictionary action and copying the results.
• Use the Dictionary Magic Variable to extract a set of values repeatedly throughout a shortcut.
• Use a dictionary to make a rich display of data in a Choose from List action, which displays the keys as menu options and the keys’ values as a preview. When you choose a key, the action passes the corresponding value into the next action.

I have always thought this. Let me know if you get an answer. Feels like it should be a basic feature.