1. 
[syn: senior high school, senior high, high, highschool, high school]
The Collaborative International Dictionary of English v.0.48:
highschool \highschool\, high school \high school\n.
   a public secondary school usually including grades 9 through
   12; as, he goes to the neighborhood highschool.
   Syn: senior high school, senior high, high, high school.
        [WordNet 1.5]
WordNet (r) 3.0 (2006):
highschool
    n 1: a public secondary school usually including grades 9
         through 12; "he goes to the neighborhood highschool" [syn:
         senior high school, senior high, high, highschool,
         high school]