Word Unit: ratio-, reason- (Latin: reckoning, to reckon; calculating, calculation; understanding; thinking)
Word Unit: rauc- (Latin: "hoarse"; hoarse cries; howl, roar; rough-sounding, harsh; loud, rough)
Word Unit: re-, red- (Latin: back, backward, again; used as a prefix)
Word Unit: real- (Latin: from res, thing, object, matter, circumstance; factual)
Word Unit: recent- + (Latin: new, fresh)
Word Unit: reciproc- (Latin: reciprocus, turning back the same way, alternating; turning backward and forward; to give, to do, to feel, or to show in return)

Inter-related cross references, directly or indirectly, involving word units meaning "another, other, different, alternating, varied, changing": ali-; allo-; alter-; allelo-; hetero-; mut-; poikilo-; vari-.

Word Unit: recti-, rect- (Latin: make right, adjust, remedy; make straight; to lead, put in a straight line; to rule)
Word Unit: recto-, rect- (Latin: straight [intestine], direct, right; that is, "the part of the large intestine that ends at the anus")
Word Unit: Reflexology: Treatment of the Feet (therapeutic applications to the feet for greater health)
Word Unit: regi-, reg-, rec-, rex- (Latin: to direct, to rule, to lead straight, to keep straight; to guide, to govern)

Cross references of word families related directly, or indirectly, to: "master, lead, leading, ruler, ruling, govern": -agogic; agon-; arch-; -crat; dom-; gov-; magist-; poten-; tyran-.

Word Unit: reminisc- (Greek > Latin: to recollect, to remember; act of recalling; to recall to memory; to remind of past events)

Related units about "memory, remembering": memor-; mne-.

Word Unit: render- (Latin: rendere from reddere, "to give back, to restore; to give up; to translate")
Word Unit: reno-, ren-, reni- (Latin: kidney or kidneys)
Word Unit: reptil-, rept- (Latin: creeping)

A cross reference of other word family units that are related directly, or indirectly, with: "snakes or other reptiles": angui-; coluber-; herpeto-; ophio-; sauro-.

Word Unit: reticulo-, reticul-, reticu-; reti-, ret-; reticulato- (Latin: net, small net; a netlike structure, a network)
Word Unit: Retina: Photoreceptor Cells (millions of photoreceptor cells residing in the human retina gather light and transmit signals to the brain)
Word Unit: retino-, retin- + (Latin: innermost tunic of the eye; from ret[e], "net" plus -ina, "like")

Related references to "eye" or "eye part" word families: blepharo-; core-; corneo-; eye, eyes; irido-; lenti-, lens-; lenticulo-; ocelli-; oculo-; op-, -optic; ophthalmo-; phaco-; uveo-.

Word Unit: retro-, retr- (Latin: back, backward, backwards; behind)
Word Unit: rhabd-, rhabdo- + (Greek: rod; twig, stick, strip, branch; rod-shaped, striated; wand)
Word Unit: rhapho-, rhaph-, rhap-, -rhaph, -rhaphy, -orrhaphy, -rrhaphy (Greek: suture, stitching, joining in a seam)