horizontal bar
US /ˌhɔːr.ɪˈzɑːn.təl ˈbɑːr/
UK /ˌhɔːr.ɪˈzɑːn.təl ˈbɑːr/

1.
a bar that is fixed horizontally, used for gymnastics or for pulling oneself up on
:
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The gymnast performed an impressive routine on the horizontal bar.
•
He installed a horizontal bar in his doorway for pull-ups.