There are 819 4-letter words containing R in the ENABLE dictionary — 21% of all 3,903 words at this length. R is a one-point tile, so the value in this list is positional rather than numerical — which of these you can play depends far more on where it fits the board than on what it scores.
The R falls in the third position more often than any other, in 337 of them. 18 of them use the letter more than once — birr, brrr, burr, carr among them, which is the case worth checking twice when a game has told you a letter is present but not how many times.
If you know more than one letter, this page stops being the fast way to find it. Enter what you have in the unscrambler — the Contains, Starts with and Ends with filters combine, and setting both length fields to 4 narrows this list to the handful your letters actually allow.
arak arbs arch arco arcs area ares arfs aria arid aril arks arms army arse arts arty arum arvo aryl brad brae brag bran bras brat braw bray bred bree bren brew brie brig brim brin brio bris brit broo bros brow brrr brut crab crag cram crap craw crew crib cris croc crop crow crud crus crux drab drag dram drat draw dray dree dreg drek drew drib drip drop drub drug drum drys eras ergo ergs erne erns eros errs erst frae frag frap frat fray free fret frig frit friz froe frog from frow frug grab grad gram gran grat gray gree grew grey grid grig grim grin grip grit grog grot grow grub grue grum ired ires irid iris irks iron kris orad oral orbs orby orca orcs ordo ores orgy orle orra orts oryx orzo pram prao prat prau pray pree prep prex prey prez prig prim proa prod prof prog prom prop pros prow sris trad tram trap tray tree tref trek tret trey trig trim trio trip trod trop trot trow troy true trug urbs urds urea urge uric urns ursa urus vrow wrap wren writ
R in the third position (337)
abri acre aero aery airn airs airt airy aura awry barb bard bare barf bark barm barn bars berg berm bird birk birl birr bora bore born bort bura burd burg burl burn burp burr burs bury byre byrl carb card care cark carl carn carp carr cars cart cere cero cire cord core corf cork corm corn cory curb curd cure curf curl curn curr curs curt darb dare dark darn dart dere derm dire dirk dirl dirt dore dork dorm dorp dorr dors dory dura dure durn duro durr earl earn ears ecru eery euro eyra eyre eyry fard fare farl farm faro fart fere fern fire firm firn firs fora forb ford fore fork form fort furl furs fury garb gars germ gird girl girn giro girt gore gorp gory guru gyre gyri gyro hard hare hark harl harm harp hart herb herd here herl herm hern hero hers hire hora horn hurl hurt inro jarl jars jerk jura jury karn kart kerb kerf kern kirk kirn kirs kore kors kuru lard lari lark lars lira lire liri lord lore lorn lory lure lurk lyre marc mare mark marl mars mart mere merk merl mire miri mirk mirs miry mora more morn mors mort mura mure murk murr narc nard nark nary nerd nori norm nurd nurl oars ogre okra ours para pard pare park parr pars part peri perk perm pert pirn pore pork porn port pure puri purl purr purs pyre sard sari sark scry sera sere serf sers shri sire sirs sora sorb sord sore sori sorn sort spry sura surd sure surf tare tarn taro tarp tars tart term tern thro thru tire tirl tiro tora torc tore tori torn toro torr tors tort tory turd turf turk turn tyre tyro vara vars vary vera verb vert very virl ward ware wark warm warn warp wars wart wary were wert wire wiry word wore work worm worn wort yard yare yarn yerk yird yirr yore yurt zarf zerk zero zori
R in the fourth position (107)
afar agar ager ajar alar amir aper aver bear beer bier blur boar boor buhr char coir czar dear deer doer door dour dyer eger emir ever ewer eyer fair fear fiar four gaur gear gnar goer guar haar hair hear heir hoar hoer hour izar jeer kbar keir kier knar knur kyar lair lear leer lehr liar lier lour maar mair moor near noir odor omer osar over oyer pair pear peer pier poor pour scar sear seer slur soar sour spar spur star stir suer tahr tear thir tier tour tsar tyer tzar user vair veer vier wair waur wear weer weir whir year your