A person who holds grudges or is inclined to bear resentment against others.
From Middle English 'grudgen' (to grudge, to murmur or complain) plus the agent suffix '-er', creating a word for someone who does the action of grudging.
The word 'grudger' reveals that medieval English speakers were so concerned about holding grudges that they named the people who did it—showing that resentment has been a documented character flaw for centuries!
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