From Longman Dictionary of Contemporary Englishbe below/under parbe below/under para) MIILLto feel a little ill or lacking in energy I’ve been feeling a little under par the last couple of weeks. b) (also not be up to par)BAD to be less good than usual or below the proper standard None of the people who’d auditioned were really up to par. The champion was playing well below par. → par
Examples from the Corpus
be below/under par• For a second year, economic growth has been substantially below par.• He later warned the council's executive committee chairman Erica Wheeler that Mrs Ware's work was below par.• I haven't been up to par since the operation. 