| ray flower |
any of the flowers around the border of the head of a composite plant such as the daisy. |
| Rayleigh wave |
a wave on the surface of a solid, such as that caused on the surface of the earth by an earthquake. |
| Raynaud's disease |
a vascular disease causing numbness and discoloration of the tips of the hands and feet, often caused by exposure to cold or by stress. |
| rayon |
a thread made by converting a solution of a natural pulp, usu. cellulose, into filament by extruding through spinnerets. [2 definitions] |
| raze |
to knock down or tear down (a structure); level. |
| razor |
an instrument that has a very sharp, replaceable blade or blades and is used for shaving away body or facial hair. [4 definitions] |
| razorback |
a wild hog of the southeastern United States, descended from domestic stock and having a sharp ridge on the back. [2 definitions] |
| razor clam |
any of various burrowing clams having long, narrow, rectangular shells. |
| razor-sharp |
extremely sharp. [2 definitions] |
| razzle-dazzle |
(informal) a flashy display used to deceive or bewilder, esp. as a strategy in football. |
| razzmatazz |
(informal) flashy or deceptive action or language; razzle-dazzle. [2 definitions] |
| Rb |
symbol of the chemical element rubidium. |
| rBGH |
abbreviation of recombinant bovine growth hormone, a genetically engineered hormone injected into dairy cows to increase their milk production. |
| RBI |
abbreviation of "run batted in" or "runs batted in." |
| RC |
abbreviation of "Roman Catholic." |
| RD |
abbreviation of "rural delivery," delivery of mail along rural routes, usu. to a roadside mailbox rather than to the door. |
| Rd. |
abbreviation of "Road," a long, narrow course, with a smooth and often paved surface, made for the passage of vehicles and people (used as a part of a proper name). |
| RDA |
abbreviation of "recommended daily allowance." |
| Re |
symbol of the chemical element rhenium. |
| re1 |
in music, the syllable that denotes the second tone of a diatonic scale. (See sol-fa.) [2 definitions] |
| re2 |
having to do with; in reference to; concerning. |