PISA definitions of:

Reading literacy

The capacity to understand, use and reflect on written texts, in order to achieve one’s goals, develop one’s knowledge and potential, and participate in society.

Mathematical literacy 

The capacity to identify and understand the role that mathematics plays in the world, make well-founded judgments, and use and engage with mathematics in ways that meet the needs of one’s life as a constructive, concerned and reflective citizen.

Scientific literacy

The capacity to use scientific knowledge, identify scientific questions and draw evidence-based conclusions, in order to understand and help make decisions about the natural world and the changes made to it through human activity.