The word "hidden" is the past tense of an irregular verb.
The word "hidden" is the past tense of an irregular verb. To determine this, you need to understand what irregular verbs are. Regular verbs follow a predictable pattern when forming their past tense (by adding "-ed" or "-d" to the base form), while irregular verbs do not follow this pattern and have their own unique forms for the past tense. In this case, "hidden" is the past tense of the irregular verb "hide".