The word "unexcused" means not having a valid reason or justification for something. It can refer to an action, behavior, mistake, error, absence, or failure that is not considered acceptable due to lack of proper explanation or legitimate cause.
Secondary students with 10 or more unexcused absences in any class during a single advisory shall receive a grade of «FA» in that subject. (dcps.dc.gov)
Three days of unexcused absences results in the virtual school reporting that student as a «truancy case» to the student's local public school district. (ncpolicywatch.com)
Secondary students with five (5) or more unexcused absences in any class during a single advisory shall receive a grade reduction in that subject. (dcps.dc.gov)