切纸刀, 切纸机长刀

[ noun ]
dull knife used to cut open the envelopes in which letters are mailed or to slit uncut pages of books
<noun.artifact>

paperknife \pa"per*knife`\ (p[=a]"p[~e]r*n[imac]f`), n.
A dull knife used to cut open the envelopes in which letters
are mailed or to slit uncut pages of books.

Syn: letter opener.
[WordNet 1.5]