(education) A school for children that serves grades between elementary school and high school, and occasionally between the former and middle school. These grades vary from anywhere from grade 4 to grade 8.

(education) An institution which provides secondary education, typically in grades 10, 11, and 12, and often also in grade 9.

Alternative form of tell tales out of school

(idiomatic) To reveal confidential or sensitive information; to gossip.

(education) A school that admits students on the basis of their academic achievements.

Of the age at which students typically attend primary or secondary school.

(mineralogy) A bronze-like lustre observed in certain minerals, such as hypersthene, due to the presence of minute parallel inclusions.

A school or college, many of whose graduates continue their education at another specific school or college, or enter a specific profession

On time; at the scheduled time. / As if on schedule, at the appropriate or expected time.

(Australia, informal) Any of the correspondence schools catering for the primary and early secondary education of children in remote and outback Australia.