B1
to allow someone to do something, or to allow something to happen
Dictionary examples:
The boss let us work overtime without pay. How kind! (0.0)
The teacher let us eat in class, but only invisible food. (0.0)
My mom finally let me get a pet rock. It's very quiet! (0.0)
Their parents let them go to the movie. (13.2)
She wanted to go but her parents wouldn't let her. (14.0)
I'm letting you stay up late, just this once. (23.1)
Don't let it upset you. (24.0)
That's Grandma at the door - could you let her in? (26.4)
He decided to let his hair grow long. (29.5)