Full of grudges; inclined to bear resentment or ill will; unforgiving and bitter.
From 'grudge' (noun) + '-ful' (suffix meaning full of or characterized by). The -ful suffix creates adjectives meaning abundance or strong presence of a quality.
Grudgeful perfectly captures someone who carries their resentments like a heavy load—the -ful suffix suggests being so completely filled with grudges that it defines their character!
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