to sneak up on

listen to the pronunciation of to sneak up on
Englisch - Türkisch
gizlice yaklaşmak
-e gizlice yaklaşmak
Englisch - Englisch
To approach a person or animal without being seen or heard

If you sneak up on me like that, you'll give me a heart attack!.

If something sneaks up on you, it happens or occurs when you are not expecting it. Sometimes our expectations sneak up on us unawares
If someone sneaks up on you, they try and approach you without being seen or heard, perhaps to surprise you or do you harm. I managed to sneak up on him when you knocked on the door. = creep up