My great grandfather picked this book off of a dead Japanese soldier in the Philippines in 1944-1945. my family has had it for the last 70 years but nobody really knows what it is. https://m.imgur.com/xlx7BPj https://m.imgur.com/XplYjyv https://m.imgur.com/tBLjc6g
It's a Japanese-English dictionary. The title reads "Comprehensive Japanese-English Dictionary (New Edition)". Each Japanese word is given explanation in Japanese and then the English translation. The Japanese owner probably used it to learn English or to translate Japanese texts to English.