Really

Full definition of really

(modal) Actually; in fact; in reality.
"He really is a true friend."
"Really? What makes you so sure?"
(informal, as an intensifier) Very (modifying an adjective); very much (modifying a verb).

1918, W. B. Maxwell, The Mirror and the Lamp Chapter 10, It was a joy to snatch some brief respite, and find himself in the rectory drawingâ€“room. Listening here was as pleasant as talking; just to watch was pleasant. The young priests who lived here wore cassocks and birettas; their faces were fine and mild, yet really strong, like the rector's face; and in their intercourse with him and his wife they seemed to be brothers.

Like its synonyms, really is, in practice, often used to preface an opinion, rather than a fact. (See also usage notes for actually.)

Increasingly people are recognising what's really important is having children.

Indicating surprise at, or requesting confirmation of, some new information; to express skepticism.A: He won the Nobel Prize yesterday.B: Really?
(colloquial, sarcastic, typically exaggerated question.) Indicating that what was just said was obvious and unnecessary; contrived incredulityA: I've just been reading Shakespeare - he's one of the best authors like, ever!B: Really.
(colloquial, chiefly US) Indicating affirmation, agreement.A: That girl talks about herself way too much.B: Really. She's a nightmare.
Indicating displeasure at another person's behaviour or statement.Well, really! How rude.

(contrived incredulity, or in ironic
sarcastic sense) you don't say, no kidding, oh really, no really