Dagger, in printing

• Printer's dagger
• Name of the "divided by" sign with a line and two dots
• Top sailor knocked back his rum?
• + or –
• Dagger from old non-Arab country
• Manuscript symbol

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Obelus \Ob"e*lus\, n.; pl. Obeli . [L., fr. Gr. 'obelo`s, prop., a spit.] (Print.) A mark [thus ---, or /]; -- so called as resembling a needle. In old MSS. or editions of the classics, it marks suspected passages or readings.

Wiktionary Word definitions in Wiktionary
n. 1 A mark ('''÷''') used to represent division in mathematics. Also used to indicate a written or printed passage, and in ancient manuscripts to mark a word or passage as spurious or doubtful. 2 A dagger mark ('''†''') used as a reference mark in printed ...

Wikipedia Word definitions in Wikipedia
Obelus is a European genus of small air-breathing land snails , terrestrial pulmonate gastropod mollusks in the family Hygromiidae , the hairy snails and their allies.