Superlative form of stocky: most stocky.(adjective)
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Use "stockiest" in a sentence
"Distributing small and medium sized packets thro poor roads, over long distances, into deep pockets of rural India and getting the stockiest to trust the mobility is a Herculean task."
"The shortest and stockiest of the three, with a shaved dome and Oakley shades, kicks me full in the chest."
"This rather withdrawn and passive child, the tallest and stockiest kid in his class, had problems telling left from right, tying his shoelaces, and copying from the board."