We had an argument because we were miscommunicating our intentions.

miscommunicating 是动词 miscommunicate 的现在分词形式。miscommunicate 由前缀 mis-（表示“错误”）和动词 communicate（交流、沟通）组成，意思是“错误地传达或交流”。miscommunicating 表示“正在发生沟通错误”或“误解对方的意思”。