blow sky-high

1. To be completely destroyed by a massive explosion. The soldiers detonated the explosives and watched the vehicle blow sky-high. Someone left the gas on, and the whole building ended up blowing sky-high. The gunpowder stored below somehow ignited, and the entire ship was blown sky-high.

2. To destroy someone or something through an explosion. In this usage, a noun or pronoun is used between "blow" and "sky-high." The tanks blew the enemy fortress sky-high. Once we set off the bomb, we'll blow those snitches sky-high! I wish I could still go visit our old family home, but the demolition crew has already blown it sky-high.

3. To undermine or negate something completely. In this usage, a noun or pronoun is used between "blow" and "sky-high." I thought I had finally discovered the problem with our experiment, but, when we tested it, the results blew my theory sky-high. Bob was considered for the promotion, but that idea was blown sky-high when he came in late to work each day this week. Man, I blew my chance at a 4.0 GPA sky-high when I signed up for this impossible math class.

blow sky-high

1. Destroy by explosion, explode, as in Once the charge is set, get away fast or you'll be blown sky-high. [Early 1800s] Also see under blow up.

2. Refute completely, as in The lab report has blown your theory sky-high. [Mid-1800s]

blow sky-high, to

To refute completely, to explode a thesis or idea. While this expression has a modern sound, it is not so very new. Andrew Jackson, in a letter of 1845, wrote, “Put your veto on them both, or you and your Secretary will be blown sky-high.”