- The definition of a frenemy is someone who is both a friend and an enemy.
An example of a frenemy is someone who you are nice to in person, but secretly compete with.
frenemy definition by American Heritage Dictionary
noun pl. fren·e·mies Informal
A person who is ostensibly friendly or collegial with someone but who is actually antagonistic or competitive.
Origin: Blend of fr(iend) + enemy.