in secret

秘密地,私下地

in place of, in point of, in power, in practice, in private, in proportion (to), in proportion to, in public, in pursuit of, in quantity, in question, in reality, in regard to, in relation to, in respect that, in return, in return for, in school, in search of, in season, in sequence, in series, in session, in shape, in short, in sight, in situ, in so far as, in some respects, in some ways, in spite of, in step, in stock, in succession, in such a way as to do, in sum, in support of, in tears, in terms of, in that,