The crossword solution for the term 'DUE PLUS 'UNO'' is TRE, which is the Italian word for three. This is a reference to the card game Uno, in which players are dealt seven cards and must match the number or color of the card on the top of the discard pile. The phrase 'due plus uno' translates to 'two plus one, ' which is the sum of the two cards in the player's hand plus the card on the top of the discard pile.