| roentgen |
a unit of x-radiation or gamma radiation equal to the amount that produces, in 0.001293 gram or one cubic centimeter of dry air at zero degree Celsius and standard atmospheric pressure, one electrostatic unit of electricity. |
| roentgenography |
photography that uses x-rays. |
| Roentgen ray |
(sometimes l.c.) see "x-ray." |
| rogation |
(usu. pl.) solemn prayers chanted during rites celebrated in some Christian churches during the three days before Ascension Day. [2 definitions] |
| roger |
used to acknowledge reception of a radio message. [2 definitions] |
| rogue |
one who is dishonest or malicious; scoundrel. [6 definitions] |
| roguery |
the conduct or an act of a rogue. [2 definitions] |
| rogues' gallery |
a collection of photographs of criminals kept by police to aid in the identification of suspects. |
| roguish |
of or having a roguelike nature; rascally. [2 definitions] |
| Rohwer Relocation Center |
an internment camp located in southeastern Arkansas that was built for the internment of Japanese-Americans during World War II between 1942 and 1944. At its peak in late 1942, there were 8,500 people being held there. |
| roil |
to make (a liquid) turbid by stirring; make cloudy or muddy. [3 definitions] |
| roily |
showing the effects of roiling; cloudy, muddy, or the like. [2 definitions] |
| roister |
to revel boisterously, noisily, and without constraint. [2 definitions] |
| role |
the character played by an actor or actress. [3 definitions] |
| role model |
one who serves as an example in the performance of a particular role. |
| role-playing |
the acting out of a role, esp. by mental health professionals or their clients as a technique for training or therapy. |
| Rolfing |
trademark for an often painful massage technique used to relieve emotional and physical stress. |
| roll |
to move by rotating or turning over repeatedly. [32 definitions] |
| roll around |
to come into existence or happen as part of a repeated cycle. |
| rollaway |
having rollers or casters for ease in bringing out from or returning to storage. |
| rollback |
an act or instance of returning prices or wages to a previous level, as by government order. |