noun

• Roi islet, Kwajalein atoll, Marshall Islands.
• (accounting) Initialism of return on investment. [(finance) A benefit gained by an investor from an investment.]
• (photography) Initialism of region of interest (in digital images, microscopy: in 3-dim-specimen reconstructions by consecutive sectioning).
• (military, espionage) Initialism of region of interest.
• (engineering) Initialism of radius of influence.
• (social service) Initialism of release of information.
• Initialism of Republic of Ireland. [A republic in western Europe, covering most of the island of Ireland, with Dublin as its capital.]