- durch Abschließen der Tür
by locking the door
- niemanden hereinlassen
let nobody in; don't let anybody in
- zu sich
to yourself
- German:
Die Phrase »sich einschließen« bedeutet »durch Abschließen der Tür niemanden zu sich hereinlassen«.
- English:
The phrase "lock yourself in" means "don't let anyone in to yourself by locking the door".
You also could lock the door from outside to let nobody in, but this is not the meaning of "sich einschließen". "Sich einschließen" means, that you are in the room that is locked.
The words "zu sich" express a direction. They mean "towards the speaker". Also the prefix "her-" in "hereinlassen" indicates, that the speaker is in the room. (The prefix "her-" means a movement towards the speaker.)