The official term used by the National Hockey League (NHL) is at even strength — abbreviated EV on official scoresheets and goaltenders' individual stats.
Teams that take a penalty, go on the power play, or pull the goalie are no longer at full strength.
Likewise, if a team on a power play scores so that the opposing penalized players all leave the penalty box, the team also returns to full strength.
This is not an official term used by the NHL but is commonly used to describe 'full strength'.
The International Ice Hockey Federation uses the abbreviation EQ in its game summaries.