The term 'Cause of Quaking' can be answered by the four letter word 'FEAR'. FEAR is an emotion that is experienced when a person is faced with danger or a threat. It is a natural response to a perceived danger and can cause physical reactions such as increased heart rate, sweating, and trembling. FEAR can also cause psychological reactions such as anxiety and panic. FEAR is a common cause of quaking, as it can cause a person to shake uncontrollably due to the intense emotions they are feeling.