an antiquated way of saying in there like swimwear meaning a sure thing; goal attainment is assured; prospects are brilliant

To be very successful very quickly, especially in regard to sex. The phrase usually refers to Errol Flynn, an Australian-born actor who was famous for his life of excess, and was acquitted of statutory rape charges.

Generally, to be quickly or especially successful, often when referring to seduction or other sexual adventures. Traditionally said to refer to classic film star and notorious womanizer Errol Flynn, though that isn't definitive.

To succeed in attaining a goal, especially in the sexual sense and for a man.

Refers to Errol Flynn the actor, noted for his large number of successful pursuits of women and girls.

In the original Tron movie, Kevin Flynn, a talented computer programmer, was transported to the Game Grid by an experimental laser in development by ENCOM, the company that fired Flynn and stole his code.

The phrase In Like Flynn can be a reference to Tron and means having access to or completing your goal.

It’s suggested by some writers that the phrase really originated with another Flynn, Edward J Flynn—“Boss” Flynn—a campaign manager for the Democratic party during FDR’s presidency. Flynn’s machine in the South Bronx in New York was so successful at winning elections that his candidates seemed to get into office automatically.

Used to project acceptance to an event or party.

Australian rhyming slang meaning that you are in with a chance.