divider

(noun) a taxonomist who classifies organisms into many groups on the basis of relatively minor characteristics. Synonyms: splitter.

(noun) a person who separates something into parts or groups.

(noun) a vertical structure that divides or separates (as a wall divides one room from another). Synonyms: partition.

(noun) a drafting instrument resembling a compass that is used for dividing lines into equal segments or for transferring measurements.