Definition: A color hue with medium wavelength of that portion of the visible spectrum lying between orange and green, evoked in the human observer by radiant energy with wavelengths of approximately 570 to 590 nanometers.
Definition: A color hue with medium-low wavelength of that portion of the visible spectrum lying between yellow and blue, evoked in the human observer by radiant energy with wavelengths of approximately 490 to 570 nanometers.
Definition: A hard, thorny or needle-like structure which occurs on various organisms. Animals such as porcupines and sea urchins grow spines as a self-defense mechanism