infrared

From infra- +‎ red.

• (UK, US, Canada) IPA^(key): /ˌɪnfɹəˈɹɛd/

  • Audio (Southern England):

    (file)

• (General Australian) IPA^(key): /ˌɪnfɹəˈɹed/

infrared (countable and uncountable, plural infrareds)

1. (uncountable) The electromagnetic radiation of a wavelength longer than visible light, but shorter than microwave radiation, having a wavelength between 700 nm and 1 mm.

   Hypernym: electromagnetic radiation

   • 1962, John Nelson Howard, Transmission of the Atmosphere in the Infrared: A Review, page 3:

     Collisions of these 'transparent' molecules with the molecules that do have absorption bands in the infrared can have a considerable influence on the intensities of the observed absorption bands.

2. (countable) A specific wavelength in this range.
   • 1924, The American Review of Tuberculosis, page 110:

     Sonne has shown that by means of the luminous rays the temperature in the tissue may be raised to a higher degree than by the use of the infrareds.

   • 2009, Alexander Grankov, Microwave Radiation of the Ocean-Atmosphere: Boundary Heat and Dynamic Interaction:

     Exposure of spectral pieces at centimeters, millimeters, and infrareds, which provide a top steadiness of the dependence "MCW radiation vs. parameter Δt" and its interannual (seasonal) dynamics.

3. (countable) A device that emits infrared radiation.
   • 2000, Pete Fowler, Keeps, page 62:

     In his room, he could install his infrareds without being discovered.

   • 2007, Ed Morawski, Solving the Security Puzzle, page 79:

     Beams are the active counterparts of passive infrareds (PIRs). Since these are active infrareds, they require two parts: a transmitter and a receiver.

   • 2020, Jenny Dorsey, The Infrared Grill Master: Recipes and Techniques for Perfectly Seared, Deliciously Smokey BBQ Every Time:

     Additionally, infrareds tend to cook food faster so there's less time to render said fat.

infrared (not comparable)

1. Having a wavelength in the infrared spectrum.

   Hyponyms: mid-infrared, near-infrared

2. (figurative, physics) Relating to very low energies or very large distances or time spans.

   Antonym: ultraviolet

   • 1986, Luis Álvarez-Gaumé, “An Introduction to Anomalies”, in G. Velo, A. S. Wightman, editors, Fundamental Problems of Gauge Field Theory, →ISBN, page 97:

     Unless otherwise stated, we will be working in Euclidean space compactified to a sphere in order to avoid infrared problems.

   • 2000, Andreas Galka, Topics in Nonlinear Time Series Analysis: With Implications for EEG Analysis, →ISBN, page 176:

     Secondly, as stated already by Osborne & Provenzale, pure k^-α-behaviour is impossible since there would have to be infinite power at zero frequency (this would correspond to an infrared catastrophe).

   • 2010, Taizo Muta, Foundations of Quantum Chromodynamics: An Introduction to Perturbative Methods in Gauge Theories, 3rd edition, →ISBN, page 331:

     Although infrared divergences are of long-distance nature, they often play an essential role in the verification of the validity of the perturbative treatment of short-distance phenomena.

• infrared on Wikipedia.Wikipedia