verb
    
    /ˈsniːk/  sneaks; sneaked or chiefly US snuck /ˈsnʌk/; sneaking
    
    always followed by an adverb or preposition [no obj] :to move quietly and secretly in order to avoid being noticed
    
    
    
    
    
    
    
    [+ obj] :to take or bring (something) secretly and often quickly
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    [no obj] Brit old-fashioned :to tell someone (such as a parent or teacher) about something wrong that someone else has done
    
    
    
    sneak up on
    
    [phrasal verb]
    
    sneak up on (someone)
    
    to approach (someone) quietly and secretly in order to avoid being noticed
    
    
    
    
    
    to approach, happen, or develop without being noticed
    
    
    
    
    
    noun
    
    plural sneaks
    
    [count] US informal :a person who acts in a secret and usually dishonest way
    
    
    
    Brit old-fashioned :tattletale
    
    American football :quarterback sneak
    
    
    
    adjective
    
    always used before a noun
    
    done while others are not paying attention