grad-, -grade, -gred, -gree, -gress

(Latin: walk, step, take steps, move around; walking or stepping)

A condition of having the teeth forward of the normal position in the arch.
Non progredi est regredi.
Not to progress is to regress.

Motto of the McCook Community College, McCook, Nebraska, USA.

ocean thermal gradient (OTG) (s) (noun) (no pl)
The temperature difference between warmer surface waters of the ocean and colder deep waters, whereas the deep waters are about 20-50 degrees Fahrenheit colder that the surface waters: In principle, the ocean thermal gradient can be utilized with various types of ocean thermal energy conversion systems.
1. In primate studies, the condition in which the body posture is upright or vertical; as, in bipedalism; especially with reference to humans.
2. Characterized by walking in a direction perpendicular to the long axis of the body; walking upright.
oxo-biodegradable (adjective), more oxo-biodegradable, most oxo-biodegradable
Regarding the possibility of certain plastics to expedite the decaying process: Unlike "normal" plastics that degrade and disintegrate very slowly, oxo-biodegradable plastics are manufactured to accelerate the destruction of the plastic product, preferably extending the destruction to the extent where the plastic is mineralized into its basic component elements.

Plastic bags which are oxo-biodegradable retain all of the advantages of normal plastic bags and, in addition, they provide effective solutions to the compost and landfill industries with minimal disruption of consumer behavioral patterns.

Walking on the phalanges; belonging to the division Phalangigrada, which consists of the camel and llama.
phi grade scale, phi scale
In geology, a logarithmic scale in which the diameter value of the Wentworth scale is replaced by the negative logarithm to the base two of the particle diameter (in millimeters), so that conventional statistical methods can be applied to sedimentary data.
photodegradable (adjective), more photodegradable, most photodegradable
Able to be decomposed into a simpler substance especially by ultraviolet light; The plastic bottle that had been thrown out of the car window was photodegradable and considered to be trash, and was done by a litterbug.
The decomposition of a substance resulting from the action of light.
physograde, physogradous (s) (noun), physogrades (pl)
In zoology, any siphonophe that has an air sac to float: The marine invertebrate of the genus Physalia, commonly known as the "Portuguese man-of-war", is considered to be a physograde with a hollow vesicular float or buoy to move.

The group of Physograda includes the oceanic Hydrozoa furnished with such floating organs.