Definition of green man:
(n) :
(chiefly UK, Ireland) A small figure of a walking man illuminated in green on a traffic light at a pedestrian crossing, indicating that it is safe to cross the road.
(n) :
(entertainment, theater) In performances and pageants, a character adorned in foliage often carrying a club, who represents a wild man of the woods.
(n) :
(now historical) A character in British folklore often depicted as a foliate head; any of certain similarly-depicted figures from other cultures, hypothesised to share a common folkloric or mythological root.
(n) :
A green spandex bodysuit, often used for green screens.