To be sound: Irish slang. To be sound is a state of existence. It usually refers to someone who willingly does a favour, asked or not, although usually unexpected - Like when you ask for one rollie and your given two, or the bouncer to an over 21s let's you in when your 20.

Alternatively, "sound" can be used as an adjective to describe a genuine, nice person.
-Man, can I have two of those Rowntrees?

-Here, you can have the rest of the packet

- AW, sound!
by Deppstache June 3, 2015
Irish slang for 'deadly' or 'cool'
who's that?
oh thats aoife she real sound.
by Caraaaaaa October 16, 2011
1. A noise.
2. A synonym for "cool," "awesome," originating in Liverpool, if I recall correctly. Either way, it's mostly used by Scousers.

Note: Please stop complaining about how we're getting the definition wrong, you yanks. Try looking it up on Wikipedia or on Google, you blithering twats.
- "Did you hear that sound, dear?"
- "The footy was well sound, weren't it, our Baz?"
- "You self proclaimed 'grammatically correct' yanks are not sound."
by LameyT August 13, 2006
Joe: can I have a chewing gum
Mike: ye bro
Joe: you sound
by Shabba dabba October 19, 2019
If somebody's sound they are a person who is a good freind and not a snitch. They are safe and wouldnt do anything bad, plus they would always have your back.
"Oi bro that daniel is sound "
"Yeah i know bro hes calm trust"
by Allai bruv January 10, 2018
a person who is funny, tough and generally a nice person
by (©_©) May 13, 2015
Sound means that you are alright and sometimes ready. If someone asks how you are feeling you can say your "sound".
"Yeah mate I'm sound."
"I've booked the table, we're sound."
by Loopylu123l July 24, 2017