A phagemid or phasmid is a DNA-based cloning vector, which has both bacteriophage and plasmid properties. These vectors carry, in addition to the origin of plasmid replication, an origin of replication derived from bacteriophage. Unlike commonly used plasmids, phagemid vectors differ by having the ability to be packaged into the capsid of a bacteriophage, due to their having a genetic sequence that signals for packaging. Phagemids are used in a variety of biotechnology applications; for example, they can be used in a molecular biology technique called "Phage Display".
The term (and new word) "phagemid" or "phagemids" was offered to the world science community by a group of Soviet scientists, who discovered them, named them, and published the article in April 1984 in Gene magazine. After that, the world community started using this term.