Term: one-quintillionth: one part in a quintillion equal parts
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: formic acid: a colorless pungent fuming vesicatory liquid acid HCOOH found naturally in ants and many plants or made catalytically from carbon monoxide and steam; used in finishing textiles and paper and in the manufacture of insecticides and fumigants
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: archduchess: a wife or widow of an archduke or a princess of the former ruling house of Austria
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: polder: low-lying land that has been reclaimed and is protected by dikes (especially in the Netherlands)
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: review: (law) a judicial reexamination of the proceedings of a court (especially by an appellate court)
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: special pleading: an argument that ignores all unfavorable evidence
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: fly rod: a long flexible fishing rod used in fly fishing
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: knobcone pine: medium-sized three-needled pine of the Pacific coast of the United States having a prominent knob on each scale of the cone
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: strop: a leather strap used to sharpen razors
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: unilateralist: an advocate of unilateralism
Broader: abstraction: a general concept formed by extracting common features from specific examples | Unrelated: inclinometer: a measuring instrument for measuring the angle of magnetic dip (as from an airplane)