- rudbeckia hirta
- rudbeckia serotina
- rudbeckia laciniata
- rudder stock
- rudbeckia laciniata hortensia
- rudder blade
- rudder post
- rudderfish
- rudder (of a boat)
- rudderpost
- rudderstock
- ruddiness
- ruddy
- ruddy turnstone
- rude and rough
- rudimentary
- rudiment
- rudolf bultmann
- rudolf karl bultmann
- rudolf hess
- rudolf christian karl diesel
- rudolf diesel
- rudolf karl virchow
- rudolf ludwig mossbauer
- rudolf steiner
- rudolf serkin
- rudolf nureyev
- rudolf virchow
- ruffed grouse
- ruefulness
- ruefully
- ruf
- rue anemone
- rudra
- ruffle up
- ruffled
- rufous rubber cup
- rug pad
- rugby ball
- rug beater
- rugelach
- rugel's plantain
- ruggedise
- ruggedisation
- rugged individualism
- ruggedization
- ruggedize
- rugulah
- ruhr valley
- run amok