Irish word for fun/enjoyment that has been brought into the English language. usu. when mixed with alcohol and/or music.
'Bhi craic agus ceol againn' : We had fun and music.
Fun doesn't really cut it though. General banter, good times had by all.
Also, a person who is good fun/great company.

Irish word, refers to good times, as well as scandal/gossip/goings on. No real English equivalent.

Irish word for banter, having a good time.
Now used in colloquial English for describing a night out drinking.

What's the crack? What's the craic?
Officialy: What's the craic? Craic being an Irish language word for good times/ gossip/music/ drinking/ debauchery of any kind/ or good clean fun.
Not specifically linked to crack of the crack-cocaine definition.
If asked this question by an Irish person, you are expected to give a reply which includes information on how you are, what you are doing, where are you going, with whom are you going there, have you any interesting gossip one might like to hear about, and so on. It is a question to which there are many possible answers, and it is used with great frequency on the Emerald Isle.

the word craic has many, many meanings. it can be a description of a night out that was brilliant e.g. last night was great craic. Or if you say 'we were having the craic with those girls' means that we were having a laugh and banter with those girls. one can also say 'how was the craic?' to enquire 'was it good' to which one answers 'the craic was 90' if it was good or 'it was no craic' if it was not enjoyable

The Craic (Pronounced ‘crack’) – An Irish word with no direct translation in English. Means partying, enjoying the company of others, having a good time and a fair amount more.

One elder statesman of the London Irish community advised us that "Craic" is an acronym as follows;

Ceol(Music)
Rince(Dance)
Amhrain(Songs)
Inis Scealta(Storytelling)
Cainte(Gossip)

Crack or craic is "fun, enjoyment, abandonment, or lighthearted mischief; often in the context of drinking or music".

This sense of the word crack is found in Irish English, Scottish English, and Geordie as well as Mackem in North East England.

In Ireland the spelling craic is now more common than crack. This spelling is also found in Scotland.

An older, related, more widespread, sense of crack is "joke", as in crack a joke or wise-crack.

Another sense of crack, found in Scottish English, is "news, gossip", which influences the common Irish expression "What's the crack?" or "How's the crack?", meaning "how are you?", "how have you been?", or "have you any news?"

The context involving 'news' and 'gossip' originated in English and Scots and came to Ireland through Ulster dialects of English and/or Scots, where the sense of 'fun' developed.

Early Irish citations from the Irish Independent relate to rural Ulster: from 1950, There was much good "crack"... in the edition of "Country Magazine" which covered Northern Ireland; or from 1955, the Duke pulled the bolt on the door of the piggery, and let Coogan's old sow out...The Duke had been sitting on top of Kelly's gate watching the crack.

It can frequently be found in the work of twentieth century Ulster writers such as Brian Friel (1980): You never saw such crack in your life, boys and Jennifer Johnston (1977): I'm sorry if I muscled in on Saturday. Did I spoil your crack?

In Newcastle upon Tyne there...