| R. | royal |
| Radiol. | radiology |
| R.A.F. | Royal Air Force |
| R.C. | Roman Catholic(ism) |
| R.C. Church | Roman Catholic Church |
| Reas. | reason(s) |
| Reb. | rebellion |
| Rebell. | rebellion |
| Rec. | record(s) |
| Reclam. | reclamation |
| Recoll. | recollection |
| Redempt. | redemption |
| redupl. | reduplicating |
| Ref. | reference |
| Ref. | reformation |
| refash. | refashioned, refashioning |
| refl. | reflexive |
| Refl. | reflection(s) |
| Refus. | refusal |
| Refut. | refutation |
| reg. | regular |
| Reg. | register |
| Regic. | regicide |
| Regist. | register |
| Regr. | register |
| rel. | related |
| rel. | relative |
| Rel. | relating |
| Relig. | religion, religious |
| Reminisc. | reminiscence(s) |
| Remonstr. | remonstrance |
| Renfrewsh. | Renfrewshire |
| Rep. | report |
| repr. | representative, representing |
| Reprod. | reproduction, reproductive |
| Rept. | report |
| Repub. | republic |
| Res. | research |
| Resid. | residence, residential |
| Ret. | return |
| Retrosp. | retrospective |
| Rev. | review |
| Rev. | revised |
| Rev. | (in the Bible) Revelation |
| Revol. | revolution |
| Rhet. | rhetoric |
| rhet. | rhetorical(ly) |
| Rhode Isl. | Rhode Island |
| Rich. | Richard |
| R.N. | Royal Navy |
| Rom. | Roman |
| Rom. | (in the Bible) Romans |
| Rom. Antiq. | Roman antiquities |
| Ross-sh. | Ross-shire |
| Roxb. | Roxburgh |
| Roy. | royal |
| Rudim. | rudiment(s) |
| Russ. | Russia, Russian |
