He had left school in junior high, ostensibly because his mother was ill. ("Delfino Il: Die in the Desert")

Answer 1

In this sentence, the term "ostensibly" is used to indicate that the reason given for the person leaving school in junior high may not be the true or actual reason. It suggests that the given reason of the mother being ill might be a cover-up or an excuse for the person's decision to drop out of school.