Third-person singular simple present indicative form of underachieve.(verb)
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Use "underachieves" in a sentence
"Then all will defend SLoan again when this team "underachieves" but like a fool for punishment i will still root and hope."
"On a two-year cycle, if the national team underachieves, there's a clamour from 60 million people."
"But the result is bound to bring more chin-stroking and head-scratching: Why does Messi's Barcelona steamroll the opposition while Messi's Argentina underachieves?"