The Collaborative International Dictionary of English v.0.48:

hr \hr\ n. [abbreviation]
   An abbreviation for hour, the period of time equal to
   1/24th of a day.

   Syn: hour, 60 minutes.
        [WordNet 1.5] HSV-1
        HS1

WordNet (r) 3.0 (2006):

hr
    n 1: a period of time equal to 1/24th of a day; "the job will
         take more than an hour" [syn: hour, hr, 60 minutes]

The Free On-line Dictionary of Computing (19 January 2023):

hr

    The country code for Croatia.

   (1999-01-27)