elope

Of a married or engaged person, to run away from home with a paramour.

Of an unmarried person, to run away secretly for the purpose of getting married with one's intended spouse; to marry in a quick or private fashion, especially without a public period of engagement.

My younger sister has left all her friends-- has eloped; has thrown herself into the power of-- of Mr. Wickham.

Although Cecilia was the youngest of the surviving Thrale daughters, she had been the first to marry, eloping to Gretna Green in 1795 with John Meredith Mostyn of neighboring Llewesog Lodge. Both were underage.

To run away from home (for any reason).

He had been intended by his father for trade, but his spirit, soaring above the occupation for which he was designed, from repining led him to resist, and from resisting, to rebel. He eloped from his friends, and contrived to enter the army.

That horrid girl of mine has been trying to run away. I had not a notion of her being such a little devil before, she seemed to have all the Vernon milkiness; but on receiving the letter in which I declared my intention about Sir James, she actually attempted to elope; at least, I cannot otherwise account for her doing it. She meant, I suppose, to go to the Clarks in Staffordshire, for she has no other acquaintances.