Final answer:
Functionally illiteracy refers to people who leave school before graduating and are unable to read and write at a necessary level for daily functioning in society.
Step-by-step explanation:
The concept of functionally illiteracy refers to people who leave school before graduating. It is the inability to read and write at a level necessary for daily functioning in society. Functionally illiterate individuals may struggle with tasks such as reading street signs, understanding job applications, or following written instructions.