n. A notional receptacle into which more than one thing accessed by the same key or short code might be dropped. When you look up a name in the phone book (for example), you typically hash it by extracting its first letter; the hash buckets are the alphabetically ordered letter sections. This is used as techspeak with respect to code that uses actual hash functions; in jargon, it is used for human associative memory as well. Thus, two things 'in the same hash bucket' may be confused with each other.
"If you hash English words only by length, you get too many common grammar words in the first couple of hash buckets."
Compare hash collision.