Funding Father In the Big Bank job, complete the heist while you and your four man crew are wearing one different "Big Bank" mask each. Unlocks the Marksman Stock for the Falcon rifle. Can be completed on any heist, not just Big Bank.
Entrapment is a reference to the caper film Entrapment. Its unlocking conditions references the iconic laser-avoiding scene in the movie.
It Takes Two to Tango is a common idiom. It also refers to the unlock conditions of the achievement, which requires cooperation between two players.
Sweet Sixteen is a special birthday celebrating a persons's sixteenth birthday in North America. It also refers to the mask it unlocks, a mask of the 16th President of the United States, Abraham Lincoln.