This is the 8233rd most frequent Japanese word.
平らげる
To eat up or finish completely.
平らげる is used here to mean 'to finish off food or consume completely', often implying efficiency or appetite when eating.
彼は一人で夕飯を平らげた。
He finished off his dinner on his own.
平らげる in this sentence metaphorically refers to thoroughly reading through books, implying a sense of completion.
私は図書館で本を平らげるのが好きだ。
I enjoy finishing off books at the library.
In this context, 平らげる is used figuratively to mean 'to overcome' or 'defeat completely', indicating decisive victory.