1) Card game terminology 2) Exposed part of a deal 3) Stud feature 
An upcard is a face up playing card. A number of card games incorporate upcards: Depending on the rules, a card that is accidentally dealt face up or otherwise revealed may become an upcard, or may be discarded, or may invalidate the entire hand. ...
The first card turned up after a deal, often to begin play or initiate a discard pile.
the dealer's exposed card, seen by all players.
The dealer's exposed, or face up, card. Opposite of Hole Card.
The dealers card that is face up.
a card properly dealt face up. Cf. · the first card turned up from the stock after the deal.