The condition of being senile, characterized by a decline in mental or physical ability due to old age.

बुढ़ापे की अवस्था

English Usage: His senility became evident when he started forgetting names and faces.

Hindi Usage: जब उसने नाम और चेहरे भूलना शुरू किया, तो उसकी बुढ़ापे की अवस्था स्पष्ट हो गई।