The rock climber manage to hold onto/grasp a firm spot before falling off the cliff.

[Jit833]

1)

Enclosed is the drawing of a door with an opening in it with an arrow pointing to the part of the opening that I am talking about. My question is, what is the bottom part of the opening called? Below is the sentence that I want to create:

1) The little boy was hanging onto a moving van. He hold onto the car by putting his hands into a gap in the door and hold the bottom part/side part of the opening to prevent falling off.

2) The rock climber manage to hold onto/grasp a firm spot before falling off the cliff.

3) The rock climber was hanging/dangling over/off the cliff but was able to prevent himself from falling off because he manage to hold onto a firm handhold.

* The highligted part of the sentences are those that I am unsure about. Hope somebody can assist me in correcting the sentences.

[emsr2d2]

I'm not sure you need any technical names for a part of a hole in a door in order for the reader to get the idea. The little boy was hanging on to the moving van by gripping (the edge of) a small gap in the van's door.