Borrowed from Latin radiatio.

• IPA: /ˌɹeɪ.di.ˈeɪ.ʃən/
• (some US dialects) IPA: /ɹaɪ.di.ˈaɪ.ʃən/
• (some Ghanaian speakers) IPA: /ɹæ.di.ˈeɪ.ʃən/

radiation

1. The shooting forth of anything from a point or surface, like diverging rays of light.

   heat radiation

2. The process of radiating waves or particles.
3. The transfer of energy via radiation.

   Coordinate terms: convection, conduction

4. Radioactive energy.
5. (evolutionary theory, countable) A rapid diversification of an ancestral species into many new forms.
   • 2016, Donald R. Prothero, The Princeton Field Guide to Prehistoric Mammals, page 136:

     The second [canid group] is the radiation of dogs in South America that began when the first canids arrived about 3 Ma, after crossing the Panama land bridge (Fig. 5.4).

• radiate
• radiative

• French: radiation
• German: Strahlung
• Italian: radiazione
• Portuguese: irradiação, radiação
• Russian: излуче́ние
• Spanish: radiación

• German: Strahlung
• Italian: radiazione
• Portuguese: radiação
• Russian: излуче́ние
• Spanish: radiación

• Italian: irraggiamento
• Russian: излуче́ние
• Spanish: radiación

• French: radiation, rayonnement
• German: Strahlung, Radiation
• Italian: radiazione
• Portuguese: radiação
• Russian: радиа́ция
• Spanish: radiación

• German: Radiation, Auffächerung