read-a-thon meaning in Information Science terminology / glossary / dictionary is:
A contraction of reading marathon, a school or library event in which young readers are given an incentive to read a certain number of pages or books within a designated period of time. The event may be tied to fund-raising, with sponsors pledged to contribute a certain amount to a worthy cause when the reading goal is met. Click here to learn about Readathon in the UK. Compare with read alound marathon.