Aircraft - here's the online Oxford definition of "green"
green
• adjective 1 of the colour between blue and yellow in the spectrum; coloured like grass. 2 covered with grass or other vegetation. 3 (Green) concerned with or supporting protection of the environment. 4 (of a plant or fruit) young or unripe. 5 in an untreated or original state; not cured, seasoned, fired, etc. 6 inexperienced or naive. 7 pale and sickly-looking.
• noun 1 green colour, pigment, or material. 2 a piece of common grassy land, especially in the centre of a village. 3 an area of smooth, very short grass immediately surrounding a hole on a golf course. 4 (greens) green vegetables. 5 (Green) a member or supporter of an environmentalist group or party.
• verb 1 make or become green. 2 make less harmful to the environment.
See adjective point 6.
