SOS
1. adjective
unable to learn; stuck on stupid US, 1994
2. noun
1
the same old stuff US, 1963.
2
a somewhat older student. Used by college students to describe, usually unkindly, students in their late twenties or older US, 2002
3. between schoolchildren, used as advice that a slip or petticoat can be seen below the hem of a skirt. An initialism of 'slip on show', playing on the emergency code 'save our souls' UK, 1979