nibble

v. chew delicately; take small fast bites; bite gently and playfully

n. small morsel of food; small quick bites; half of a byte, unit of information having four bits (Computers)

A nibble (or less commonly, nybble) is the computing term for a four-bit aggregation, or half an octet (an octet being an 8-bit byte). As a nibble contains 4 bits, there are sixteen (24) possible values, so a nibble corresponds to a single hexadecimal digit (thus, it is often referred to as a "hex digit" or "hexit").
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Noun
1. a small byte
(synonym) nybble
(hypernym) computer memory unit
(part-holonym) byte
(derivation) pick, piece
2. gentle biting
(hypernym) bite, chomp
Verb
1. bite off very small pieces; "She nibbled on her cracker"
(hypernym) bite, seize with teeth
(derivation) nybble
2. bite gently; "The woman tenderly nibbled at her baby's ear"
(hypernym) bite, seize with teeth
3. eat intermittently; take small bites of; "He pieced at the sandwich all morning"; "She never eats a full meal--she just nibbles"
(synonym) pick, piece
(hypernym) eat
(derivation) nybble

(v. t.)
To bite upon something gently or cautiously; to eat a little of a thing, as by taking small bits cautiously; as, fishes nibble at the bait.
  

(v. t.)
To bite by little at a time; to seize gently with the mouth; to eat slowly or in small bits.
  

(n.)
A small or cautious bite.
  

Part of a byte, usually half of a byte. (Obsolete)