absence

(noun) the state of being absent. Example: "He was surprised by the absence of any explanation."

(noun) failure to be present.

(noun) the time interval during which something or somebody is away. Example: "He visited during my absence."

(noun) the occurrence of an abrupt, transient loss or impairment of consciousness (which is not subsequently remembered), sometimes with light twitching, fluttering eyelids, etc.; common in petit mal epilepsy. Synonyms: absence seizure.