"gruffest" in the adjective sense
1. crusty, curmudgeonly, gruff, ill-humored, ill-humoured
brusque and surly and forbidding
"crusty remarks"
"a crusty old man"
"his curmudgeonly temper"
"gruff manner"
"a gruff reply"
2. gruff, hoarse, husky
deep and harsh sounding as if from shouting or illness or emotion
"gruff voices"
"the dog's gruff barking"
"hoarse cries"
"makes all the instruments sound powerful but husky"- Virgil Thomson
Source: WordNet® (An amazing lexical database of English)
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