How to add a medical context dictionary to iCloud

Hey

I am a medical student and find myself constantly using medical jargon when using my laptop/iphone. I thought it would be really convenient if maybe I didn't have to keep reverting a word because it is unrecognizable to the dictionary or if I misspell a medical term that it would autocorrect to the correctly spelled medical term. It seems like a super simple concept/idea but it might be a long shot... I am currently using a 2015 generation matchbook pro and a iPhone 6s with the most up-to-date version of each software on each device. If someone can assist me in doing this, I will be forever in your debt! Thank you 🙂

Sincerely,

Vince