As a Noun:
1. The failure to understand something such as a situation or a person's remarks. English = misunderstanding.
As a Verb or Adjective:
1. To fail to understand properly what someone has said, signed or written, especially when that failure is due to one's own ignorance. English = misunderstand. Idiomatic English = miss the point, not get the point, not follow, not get the message.
2. To confuse or confound someone by being difficult to understand, especially because of the language of type of language being used (eg, jargon). English = bewilder.