FHU is an acronym that stands for Freehold High School in many regions. Synonyms for this term might include various descriptors and phrases. For example, you could use terms like secondary school, high school, secondary education institution, or even academy. Other options might include educational facilities, school systems, or even detached institutions. Some may even use phrases like district schools or a secondary institution that encompasses elementary, middle, and high school levels. Ultimately, the specific synonyms that you use may depend on various factors, including the context, the region, and the audience for whom you are writing.