LET IN

let in = allow to enter

examples:

• My overcoat has a hole and lets in water.
• Your boots let in water in the rain. You should buy a new pair.
• The light in that room was impressive. There were four windows, one on each wall, that let in sunlight from all directions.
• Open the windows. Let some fresh air in. 
• Open the door! Let me in!
• Please, let me in. I want to apologise.
• Who let you in? I didn 't hear the doorbell.
• Don 't let the children in if they don 't clean their shoes first.
• This nice window on the roof lets air and light in all day.
• I took his keys and told him not to come to my house again. Still, when I was away, he let himself in.