The word is rabbit. It contains six letters.
Rabbit.
fodder! fatter
collar dollar
raunch
Adder (snake) Alligator Ant bear (anteater) Anteater
killer, kilter, kisser
Some six letter words ending in R are:antleranswerbeaverbetterbitterborderbutlerbuttercratercursorcuterfalterfiltergarterhamperhatterhealerheaterhotterjuniorkinderladderlardermurderporterpotter
Gibraltar ends with an r.
There could be multiple answers to this. RACISM is one such word starting with R and ending with M.
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 5 words with the pattern R---OR. That is, six letter words with 1st letter R and 5th letter O and 6th letter R. In alphabetical order, they are: rancor raptor rector rhetor rizzor
Scarbeardearfeargearhearnearpearrearseartearwearyear.
appearbrotherchowderdrifteremperorflickerflustergrinderhoarderintegerjanitorlaundrymufflerneitherprinterremoverslenderteachervaulterwhisperyounger
spider