Sickle is an email filter tool that operates over IMAP connections. The filtering instructions themselves are specified in Perl, and make use of data structures populated by Sickle. Properties that can be examined include email addresses, names, message flags , and dates.
A reaping instrument consisting of a steel blade curved into the form of a hook, and having a handle fitted on a tang. The sickle has one side of the blade notched, so as always to sharpen with a serrated edge. Cf. Reaping hook, under Reap.
A tool with a curved blade used to cut grass or grain corps.