Evergreen (The Twilight Zone) definition

Of plants, especially trees, that do not shed their leaves seasonally.
- 1902: Henry Van Dyke, The Blue Flower http://etext.lib.virginia.edu/etcbin/ot2www-pubeng?specfile=/texts/english/modeng/publicsearch/modengpub.o2w&act=text&offset=287397704&textreg=2&query=+evergreen&id=DykBlue
  
  ...these three little creeping vines put forth their hands with joy, and spread over rock and hillock and twisted tree-root and mouldering log, in cloaks and scarves and wreaths of tiny evergreen, glossy leaves.
Continually fresh or self-renewing; often used metaphorically.
Suitable for transmission at any time; not urgent or time-dependent.
- 2001, Christopher H Sterling, John M Kittross, Stay Tuned (Lawrence Erlbaum Associates 2001, p. 654)
  
  Another change in the news was emphasis on “evergreen” features involving attractive children or animals, parades or fireworks, as well as local developments.

A tree or shrub that does not shed its leaves or needles seasonally.
More specifically, a conifer tree.
- 1858: Henry David Thoreau, The Maine Woods http://etext.lib.virginia.edu/etcbin/ot2www-pubeng?specfile=/texts/english/modeng/publicsearch/modengpub.o2w&act=text&offset=618074587&textreg=1&query=+evergreen&id=ThoMain
  
  The spruce and fir trees crowded to the track on each side to welcome us, the arbor- vitae, with its changing leaves, prompted us to make haste, and the sight of the canoe-birch gave us spirits to do so. Sometimes an evergreen just fallen lay across the track with its rich burden of cones, looking, still, fuller of life than our trees in the most favorable positions.
- 1958: Chuck Berry, Johnny B. Goode
  
  Deep down in Louisiana, close to New Orleans,
  
  Way back up in the woods among the evergreens,
  
  There stood a log cabin made of earth and wood
  
  Where lived a country boy named Johnny B. Goode
A television news story that can be shown at any time there is available space as it is not time-sensitive.

To extend the term of a patent beyond the normal legal limit, usually through repeated small modifications.
To set the repayment rate of a loan at or below the interest rate, so low that the principal will never be repaid.

evergreen