(Buteo albonotatus), a medium-sized hawk of warm, dry parts of the Americas

A concept developed by Soviet psychologist and social constructivist Lev Vygotsky: the difference between what a learner can do without help and what he or she can do with help.

(embryology) A region of mesenchymal connective tissue that carries instructions which direct the developing limb bud to form along the anterior-posterior axis.

The zone near the equator where mixing occurs between the two tropical zones of the atmosphere.

(rare) A massage technique in which heated stones and herbal balls are applied to the feet and lower leg using specific finger and hand techniques, as well as movement manipulation.

plural of galactic habitable zone

(astrobiology, astronomy) the restricted zone around a sun where the ever shifting habitable zone is always present throughout the main sequence lifetime of that star.

plural of continuously habitable zone

(astrobiology, astronomy) the zone in a disk galaxy lying within the disk which is neither too far from the core so as to be lacking in heavier elements, nor too close to the core as to experience excessive exposures to supernovae, where intelligent life may develop

plural of zone of polarizing activity