Synonyms for On the up-and-up:

• adj.

  •even-handed (adjective)
  • fair,
  • aboveboard,
  • square,
  • honest,
  • reasonable,
  • balanced,
  • equitable,
  • straight,
  • fair-and-square,
  • upright,
  • right,
  • honorable,
  • unprejudiced,
  • disinterested,
  • objective,
  • virtuous,
  • neutral,
  • just,
  • justifiable,
  • unbiased.
  •genuine (adjective)
  • honest-to-god.
  •honest-to-God (adjective)
  • authentic,
  • accurate,
  • factual,
  • authenticated,
  • actual,
  • absolute,
  • valid,
  • certified,
  • bona fide,
  • legitimate,
  • kosher,
  • legit,
  • real,
  • true,
  • unquestionable,
  • certain,
  • positive,
  • official.
  •honorable (adjective)
  • conscientious,
  • honored,
  • righteous,
  • acclaimed,
  • unstained,
  • forthright,
  • straightforward,
  • notable,
  • celebrated,
  • reliable,
  • trustworthy,
  • illustrious,
  • noble,
  • esteemed,
  • truthful,
  • sterling,
  • faithful,
  • eminent,
  • distinguished,
  • chivalrous,
  • dependable,
  • knightly,
  • respectable,
  • principled,
  • sincere.
  •on the level (adjective)
  • straight-shooting,
  • accredited,
  • accepted,
  • proper,
  • sanctioned,
  • fair and square,
  • lawful,
  • authorized,
  • verifiable.

• Other synonyms:

  •adj.
  • ethical,
  • honest-to-goodness,
  • impartial,
  • nonpartisan,
  • real stuff,
  • on the up and up,
  • really truly,
  • high-principled,
  • law-abiding,
  • sure-enough,
  • even-handed,
  • on the level,
  • for real,
  • non-partisan,
  • of good repute,
  • on up and up,
  • on up-and-up,
  • right as rain,
  • straight shooting,
  • sure enough,
  • for-sure,
  • no buts about it,
  • really-truly,
  • sure-thing.

Antonyms for On the up-and-up:

• adj.

  • honorable
    dishonest, untrustworthy, devious, unethical, irresponsible, unreliable, bad, unjust, unknown, immoral, deceptive, corrupt, lowly.