wait is 半球 the same as a half day off or the train?

so i saw 半球 in an anime and i think it means hemisphere? but wait i heard somewhere that it actually means a half-day off from work or maybe a train company?? idk i might be crazy. also i keep getting it mixed up with stuff like 簡易 and random furniture words like 家具... are they related? like is a hemisphere just a giant piece of earth furniture? please help im so lost lol