undefined          
adjective uk/ˌʌn.dɪˈfaɪnd/ us/ˌʌn.dɪˈfaɪnd/
 未阐明的,未作解释的
not clearly described, stated, or known
  The business is attempting to gauge how large a share of a new and largely undefined market it can seize. 该公司正试图衡量自己能够在一个基本上不明朗的新市场中占据多大份额。 
  未下定义的
not having been given a definition (= a statement explaining the meaning of something)
  Certain words in the dictionary remain undefined, with only their form shown. 词典中的某些单词仍未定义,只显示了它们的形式。