double-down

Verb

double down (third-person singular simple present doubles down or (nonstandard) double downs, present participle doubling down or (nonstandard) double downing, simple past and past participle doubled down or (nonstandard) double downed)

1. (intransitive) To double one's wager, particularly, the name of a specific doubling bet allowed in blackjack.
   • He'd bet three thousand and double down to six thousand, all of it hanging on the turn of the next card.1999, Frederick Barthelme, Steven Barthelme, Double Down: Reflections on Gambling and Loss, →ISBN, page 66
2. (broadly, figuratively, intransitive) To significantly increase a risk, investment, or other commitment; to respond to a challenge (e.g. to an opinion) by reinforcing or extending one's position rather than moderating it.
   • Hillary Clinton, John Edwards and Barack Obama all want to get out of Iraq. They all want to double down in Afghanistan.2007 April 12, Peter Beinart, “The Kosovo Conundrum”, in Time