difficult to see or find:
the use of hidden cameras
Some areas can hold hidden dangers for dogs.
the hidden meaning behind his words
Be on the lookout for hidden costs in hotel bills.
not easy to notice or realize:
He wants each pupil to have the chance to discover hidden talents.
the secret purpose behind a plan or activity that you do not tell other people about - used to show disapproval:
Voters suspected a hidden political agenda.
Was there a hidden agenda behind this decision?