A leg is a person who you like but
don't know their name. Jackleg is the same but a person who you
don't like and don't know their name. Also, legfest - more than 3 people working together that you don't know any of there names.
Construction
job lingo of meeting a lot of people that you can't remember their names
1.) Hey leg do you mind giving me a
hand to move this pipe.
2.) Do you know that jackleg over there helping
us out.
3.) What's up
legs, looks like a legfest going on.