Never mind... I ended up just deleting the entire activity and putting a new one back in. Seemed easier than deleting 10 entries for each student, and there are 29 students.
Glossary
Delete all Glossary entries
ဆွေးနွေးပွဲ သော့ခတ်ထားသောကြောင့် အကြောင်းပြန်၍ မရတော့ပါ။