AnkiMobile now supports adding note through URL scheme, which makes it possible to add words to Anki with the help of Workflow iOS with much ease.
Basically the flow runs in this way:
Select a word while you are reading on iOS device -> Share -> Run Workflow -> Get word pronunciation and definition using this API -> Save to Anki
You can get this workflow here, then deploy your own dictionary service and alter the Anki x-callback scheme based on your own profile/deck/field.
Behind dict is mw-dict, which serializes word definition into a developer-friendly and readable json format from Merriam Webster's Developer API.
yarn
cp config.sample.js config.js # insert your API key from dictionaryapi.com
node index.js --port=3001