Parasitic is a term used to describe organisms that live off of other organisms, often to the detriment of the host organism. LEECHLIKE and BLOODSUCKING are two terms that can be used to describe this type of relationship. A LEECHLIKE organism is one that attaches itself to its host and feeds off of its blood, while a BLOODSUCKING organism is one that feeds off of the blood of its host. Both of these terms are used to describe the PARASITIC relationship between an organism and its host.