Plainly
look up a word, understand it — no rabbit hole
diagnosis
verbdie-uhg-NOH-sis
meaning in plain English
To figure out what illness a sick person has.
Think 'diagnosis' as 'dig into the illness'—you dig (diagn) to find the cause, like a doctor digging for clues.
for example
The doctor diagnoses the flu after listening to her cough.
When a doctor makes a diagnosis, they are matching the patient’s clues to the right disease. It’s the process of finding out what’s making someone sick.