re·al·ly
(rē′ə-lē′, rē′lē)adv.1. In actual truth or fact: There isn't really a lake there; it's just a mirage.
2. To a great degree; very much: I would really like to meet your sister.
3. Very; utterly: That was a really enjoyable evening.
4. Without a doubt; indeed: Really, I don't want more dessert.
interj. Used to express surprise, skepticism, displeasure, or interest: "I've been reading her diary." "Really?"
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
really
(ˈrɪəlɪ) adv1. in reality; in actuality; assuredly: it's really quite harmless.
2. truly; genuinely: really beautiful.
interj3. an exclamation of dismay, disapproval, doubt, surprise, etc
4. not really? an exclamation of surprise or polite doubt
Usage: In strict usage adverbs of degree such as really, too, quite, very, and extremely are used only to qualify adjectives: he is really happy; she is very sad. By this rule, these words should not be used to qualify past participles that follow the verb to be, since they would then be technically qualifying verbs. With the exception of certain participles, such as tired or disappointed, that have come to be regarded as adjectives, all other past participles are qualified by adverbs such as much, greatly, seriously, or excessively: he has been much (not really) inconvenienced; she has been excessively (not too) criticized
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
re`-al•ly′
v. re•al•ly
(ˈri ə li, ˈri li)
adv. 1. actually: things as they really are.
2. genuinely; truly: a really hot day.
3. indeed: Really, this is too much.
interj. 4. (used to express surprise, reproof, etc.)
[1400–50]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
really
You use really in conversation and in less formal writing to emphasize something that you are saying.
Really usually goes in front of a verb, or in front of an adjective or adverb.
I really enjoyed that.
It was really good.
He did it really carefully.
You can put really in front of or after an auxiliary verb. For example, you can say 'He really is coming' or 'He is really coming'. There is no difference in meaning.
We really are expecting it to be a best-seller.
It would really be too much trouble.
Be Careful!
'Really' is not usually used in formal writing. Words such as very or extremely are usually used instead.
You can say 'Really?' to show that you are surprised by something that someone has said.
'I think he likes you.' 'Really? He hardly spoke to me all day.'
Collins COBUILD English Usage © HarperCollins Publishers 1992, 2004, 2011, 2012