Meanings of blundering over in English

You're at my mercy, Daniel shouted as he came blundering over the rise.

Down he goes under my leg- Igoblundering over him twenty miles an hour.

I want to sit a horse, rearing, or plunging, or blundering over rough ground.

When I entered, Laura was conversing with a group of dashing young men, who were blundering over a book of charades.

There sat old Mazey, with his spectacles low on his nose, and his knotty old hands blundering over the rigging of his model ship.

He was not an orator: he had an atrocious delivery, and rarely got through the briefest epistle, or collect even, without blundering over a preposition.

"You have retained much, Señora," exclaimed Talbot, blundering over the first compliment he he had paid her in twenty years.

"Boles, Mr. Student," she said, as if offended with me for blundering over the name, "he is Boles-myyoung man."