pa-reg'-me-non noun: The juxtaposition of words that have the same roots.

the present presentation
the preceding precedent
an emerging emergency
a memorable memorial
pathetic apathy
inappropriate approbation
the essential essence
the presiding President
an impractical practice
a fabulous fable
improvised provisions
collected recollections
innumerable numbers
a gregarious congregation
an inconsequential sequence
ridiculous ridicule
an imposing impostor
irrational rationing
the facing fašade
ample amplitude
an unnatural nature
a specific specification
the authorized author
a methodical method
the definitive definition
a reasonable reason
an urbane suburb
a sensational sensation
a tactful tactician
potentially potent
a genteel gentleman
a questionable quest
an irregular regulation
a pitiful pittance
an uncivilized civilization
a famous defamer
a pugnacious pugilist
a pedestrian peddler
sophisticated philosophy
a significant sign
a resounding sound
dictatorial interdiction