R

R is the eighteenth letter of the Latin alphabet. Semitic Rêš (the head) developed into Greek Ρω (Rô). The sound value /r/ however was maintained in Greek as well as Etruscan and Latin. Romeo represents the letter R in the NATO phonetic alphabet.

Meanings for R

\n* In biochemistry, R is the symbol for arginine.\n* In calendars, R is often used as an abbreviation for Thursday instead of T, to avoid confusion with Tuesday.\n* In chemistry,\n** R denotes the molar gas constant.\n** In organic chemistry, R is the symbol for the hydrocarbon chain.\n* in chess, R is a notation symbol for the rook piece\n* In commerce, R with an enclosing circle, ®, denotes a registered trademark.\n* In computing, R is the name of a statistical programming language; see R (programming language)\n* In electrical engineering, R is often the variable for electrical resistance\n* In film, R is a rating given for films given by the Motion Picture Association of America; see R (rating)\n* In financial securities, R is the stock symbol for Ryder Systems Inc\n* In geometry, r is often a variable for the radius of a circle\n* In law, R stands for Rex (king) or Regina (queen) in court citations incountries that recognize the British monarch as head of state.\n* In mathematics, blackboard bold represents the real numbers\n* In navigation, R denotes the relative direction "right"; see left and right.\n* In physics, R is the symbol for roentgen, a unit of dosage of X-rays or gamma radiation.\n* In radiocommunication, R is one of the ITU prefixes allocated to Russia. See also: Uvular R, Я Two-letter combinations starting with R:\n*ra rb rc rd re rf rg rh ri rj rk rl rm rn ro rp rq rr rs rt ru rv rw rx ry rz