살갑다, salgapda, is what you call somebody warm and easy to be near. Open the dictionary, though, and another meaning comes first: of a house or a piece of furniture, roomier inside than it looks from the outside.
Which turns out to be the better definition of the person as well. Plain frontage, nothing announced. You get in and there is far more floor than you had any reason to expect, and other people are already sitting on it.
Quiet people can be salgapda and talkative ones can be cold, so it is not a matter of manner. It is square footage.
You make fewer mistakes around that kind of person. Or rather you make the same number, and they cost less.