Typically used in Scotland to describe someone who participates in theatre/performing and tends to be quite obnoxious about it, also can be referred to as a 'drama wain'.
Tend to be overly excited and smiling all the time and melodramatic and attention seeking when in a negative mood.
More geared towards the ones who have been "doing it all their life" which means since they were children, hence wean / wain.
The Musical Theatre ones are the worst.
"I've done theatre all my life! I actually have rehearsals now, I'm the leading role in Fiddler on the Roof! I've also done loads of other musicals and plays and pantomimes, since I was just a baby, I was born for it!"
"You're actual such a drama wean."
A word misunderstood by the greater perverted american male who has raging hormones and and can't control his desire, in actuality it is the excess skin which kind of hangs of your elbow when your arm is straight