This is a transliteration into Tagalog of the English word.
háy-is·kúl
háy-iskúl
high school
Most Filipinos write this as one word — hayskul — but the Commmission on Filipino Language (KWF) has stated that HAY-ISKUL is considered standard.
This refers to secondary school, where students are educated before starting college or getting jobs.
KAHULUGAN SA TAGALOG
háy-iskúl: mataas na paaralan