a slap on the wrist
• a mild reprimand or punishment.
• "the few perpetrators prosecuted only got a slap on the wrist"
Similar:
reprimand,
rebuke,
reproof,
scolding,
admonition,
admonishment,
reproval,
telling-off,
rap over the knuckles,
dressing-down,
ticking off,
wigging,
serve,
bollocking,
