(physics) The stage in the flow or a fluid during which it changes from laminar to turbulent / (geology) The region between the upper and lower mantle characterized by a rapid increase in density

(botany) The area in a plant's leaf, stem, or fruit stalk, where the abscission layer if formed along with weakened sclerenchyma, absent collenchyma, and dense cytoplasm.

(of a tidal coast) The intertidal zone / (of a non-flowing, non-tidal body of water) The zone of shallow water to the limit at which plants root.

The mass of water in a lake or ocean not close to the bottom and not near the shore.

Synonym of war zone

A trance-like state of immersion reached through intense interaction with gambling machines.

simple past tense and past participle of red-zone

An area to which access is restricted because it is contaminated with radiation or a chemical or biological biohazard. / An area where fighting or hostilities are likely to erupt.

(Christchurch, New Zealand) To categorize as too damaged to repair, and requiring the owners to vacate (a property).

present participle of flood the zone