Rí·o or Ri·o 
(rēō)
(rēō) For names of South American rivers, see the specific element; for example, Plata, Río de la, or Roosevelt, Rio.
- phosphorylative
- phot
- phot-
- phot-
- photic
- photo
- photo-
- photoactive
- photoactivity
- photoaged
- photoaging
- photoautotroph
- photoautotrophic
- photoautotrophically
- photobiologic
- photobiological
- photobiology
- photobomb
- photocell
- photochemical
- photochemically
- photochemical smog
- photochemistry
- photochromatic
- photochromism