klus'-ter:
⇒See the definition of cluster in the KJV Dictionary
(1) 'eshkol; compare proper nameVALE OF ESHCOL . (which see), from root meaning "to bind together." A cluster or bunch of grapes (Ge 40:10; Nu 13:23; Isa 65:8; Song 7:8; Mic 7:1, etc.); a cluster of henna flowers (Song 1:14); a cluster of dates (Song 7:7). "Their grapes are grapes of gall, their clusters are bitter." (De 32:32).
(2) botrus, "gather the clusters of the vine of the earth" (Re 14:18).
⇒See also the McClintock and Strong Biblical Cyclopedia.
The "cluster of raisins" (tsimmuqim) of 1Sa 25:18; 30:12, should rather be "raisin cakes" or "dried raisins."
E. W. G. Masterman