n. | 1. a school that includes grades 9 or 10 through 12 2. a secondary school, for pupils aged 11 to 16, 17, or 18 3. in the U.S., a school for children between the ages of 14 and 18. High schools usually have a four-year program divided into grades 9 through 12 4. in the U.K., a school for children between the ages of 11 and 18 1. a school that includes grades 9 or 10 through 12 2. a secondary school, for pupils aged 11 to 16, 17, or 18 3. in the U.S., a school for children between the ages of 14 and 18. High schools usually have a four-year program divided into grades 9 through 12 4. in the U.K., a school for children between the ages of 11 and 18 |