The definition of animosity is strong ill will or dislike.(noun)
Two neighbors constantly fighting over a property line are an example of people who are sharing a feeling of animosity.
See animosity in Webster's New World College Dictionary
noun pl. animosities
Origin: ME animosite < L animositas, boldness, spirit < animosus, spirited < animus: see animus
See animosity in American Heritage Dictionary 4
noun pl. an·i·mos·i·ties
Origin: Middle English animosite
Origin: , from Old French
Origin: , from Late Latin animōsitās, courage
Origin: , from Latin animōsus, bold
Origin: , from animus, soul, spirit; see anə- in Indo-European roots.
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