Take it from an actual stagehand, it's front of house irregardless of venue. I'm sure there are different names but if you work in the industry, that's front of house.
Front of house. The left and right portions of the stage from the crowd perspective are called house left and house right. Left and right portions of the stage perspective is stage left and stage right. The terms are used a lot when setting up lights and calibrating sound.
Might be regional. I work at festivals in the UK and it's called the sound stage here.
ETA - should also add, FOH means something else at UK festivals, it's the non tech parts, so the catering are FOH, the bar is FOH, FOH staff cannot enter the soundstage.
We called it the PA. Back in the day when I was involved in organising and setting up parties and small concerts. (each about once a year).
Not very accurate (looked it up just now) , but you might hear it referred to as such.