• noun a way in which objects or data or structures are organised, usually with the most important or highest priority or most general item at the top, then working down a tree structure


  • A group or series which is ranked or classified. The usual structure is from highest to lowest, with each successive level below being subordinate to that above it.

Information & Library Science

  • noun a system of ranking things or people according to their importance


  • noun a series of items ranged in order of importance


  • noun the arrangement of an organisation in various ranks, with fewer and fewer people in the higher ranks

Origin & History of “hierarchy”

Greek hierós meant ‘sacred, holy’. Combined with -arkhēs ‘ruling’ (as in English archbishop) it produced hierárkhēs ‘chief priest’. A derivative of this, hierarkhíā, passed via medieval Latin hierarchia and Old French ierarchie into middle English as ierarchie (the modern spelling was introduced on the basis of the Latin form in the 16th century). At first the word was used in English for the medieval categorization of angels (into cherubs and seraphs, powers and dominions, etc), and it was not until the early 17th century that it was applied to the clergy and their grades and ranks. The metaphorical use for any graded system soon followed.