paperknife

Từ điển Oxford Advanced Learner 8th

paper·knife [paperknife paperknives] BrE [ˈpeɪpənaɪf] NAmE [ˈpeɪpərnaɪf] noun (pl. paper·knives)(especially BrE) (NAmE usually ˈletter opener)
a knife used for opening envelopes
See also: ↑letter opener