acephalous          
adjective  formal uk/ˌeɪˈsef.əl.əs/ us/eɪˈsef.əl.əs/
 无头的
without a head
  an acephalous monster 无头怪兽 
  无领导的
without a leader
  They live in small groups with an acephalous social organization. 他们三五成群地生活在一起,形成一种无领导的社会组织。 
 an informal, acephalous committee 非正式的无领导的委员会 
 - More examples
 - Some of the creatures are very incompletely formed, especially those which are acephalous.
 - The term MOOC, coined about 2008, was originally applied to informal acephalous online-learning communities.
 - This is essentially a transnational fascist radicalizing movement. But it's an acephalous movement. It has no head.