fallback

• fall-back

From the verb fall back.

• IPA^(key): /ˈfɔːl.bæk/

fallback (countable and uncountable, plural fallbacks)

1. An act of falling back.

   A failure of one of the rocket's first-stage engines just after liftoff would result in a destructive pad fallback.

   The black hole formed as a result of fallback of ejecta onto the neutron star initially created by the supernova explosion.

2. A backup plan or contingency strategy; an alternative which can be used if something goes wrong with the main plan; a recourse.

   As a fallback, I suppose we can use typewriters if the word processing system fails.

3. (construction) A reduction in bitumen softening point, sometimes called refluxing or overheating, in a relatively closed container.
4. Pulverised material that falls back to earth after a nuclear explosion; fallout.
   • 1970, Nuclear Science Abstracts, page 3595:

     Particle size distributions of fallback and ejecta were determined principally by mechanical sieving and weighing.

• (act of falling back): ebbing, recession, retreat
• (backup plan): back-up/backup, plan B, recourse. Hypernyms: see Thesaurus:option

fallback (not comparable)

1. That can be resorted to as a fallback.

   a fallback plan

• alternate/alternative, back-up/backup, secondary

• fallback font

fallback

1. Misspelling of fall back.

• backfall