[MeatteCen]

I think English uses "afraid of" and "respecting" instead.

Two teenage girls were running around in my apartment building a few weeks ago, and let themselves into my friend's room, without knocking. These two girls would be considered ไม่เกรงใจใคร or not scared of anyone/disrespectful.

เกรงใจ is what would tell most of us that the "correct" way would be to knock and wait for an invitation into the room, because it is not our room.

A person would give up their seat to an elder because of being เกรงใจเขา