sneak

sneak past tense and past participle sneaked or snuck American English

1

go secretly

 [intransitive always + adverb/preposition] to go somewhere secretly and quietly in order to avoid being seen or heard[= creep]

sneak in/out/away etc

They sneaked off without paying!

She snuck out of the house once her parents were asleep.

2

take/give secretly

 [transitive] to hide something and take it somewhere or give it to someone secretly:

I snuck her a note.

sneak something through/past etc somebody/something

Douglas had sneaked his camera into the show.

3

 sneak a look/glance/peek

to look at something quickly and secretly, especially something that you are not supposed to see:

He sneaked a look at her.

4

steal

 [transitive] informal to quickly and secretly steal something unimportant or of little value

sneak something from somebody

We used to sneak cigarettes from Dad.

sneak on somebody 

phrasal verb

to tell someone such as a parent or teacher about something that another person has done wrong, because you want to cause trouble for that person:

A little brat named Oliver sneaked on me.

sneak up 

phrasal verb

to come near someone very quietly, so that they do not see you until you reach them

sneak up on/behind etc

I wish you wouldn't sneak up on me like that!

You keep an eye out while I sneak in