Noun
(card games) A bid in which the bidder asserts that he or she will not take any tricks.
(neologism) A person who has their genitals (and sometimes nipples) surgically removed (nullification) as a form of body modification.
Source: en.wiktionary.orgDouble nullo may be called by one partner even if the other partner passes. Source: Internet
In this instance the player who calls nullo draws in his/her partner and both must play and not take any tricks. Source: Internet