Definition from Wiktionary, the free dictionary
Etymology 1 
Perhaps from Middle Low German nibbelen (“to gnaw”).
- Rhymes: -ɪbəl
nibble (plural nibbles)
- A small, quick bite taken with the front teeth.
- (in the plural, nibbles) Small snacks such as crisps/potato chips or nuts, often eaten to accompany drinks.
Derived terms 
a small, quick bite taken with the front teeth
- (transitive) To eat with small, quick bites.
- The rabbit nibbled the lettuce.
- (transitive) To bite lightly.
- He nibbled at my neck and made me shiver.
eat with small bites
Etymology 2 
Alternative forms 
(computing) A unit of memory equal to half a byte, or four bits