1
general::
Pass time aimlessly. For example, There was nothing to do, so I sat around killing time until dinner was ready. This idiom was first recorded about 1768.
American Heritage Idioms
2
general::
Phrase(s): kill time
Fig. to use something up, especially time. • I killed time reading a novel. • The employees were not encouraged to kill time.
McGrawhill's American Idioms And Phrasal Verbs