hydroid

[hahy-droid] /ˈhaɪ drɔɪd/
adjective
1.
noting or pertaining to that form of hydrozoan that is asexual and grows into branching colonies by budding.
noun
2.
the phase of a hydrozoan coelenterate that consists of polyp forms usually growing as an attached colony.
Origin
1860-65; hydr(a) + -oid
Examples from the web for hydroid
  • High efficiency gas-fired tankless boiler for water and hydroid space heating.
  • More algal, hydroid, and sponge growth was present on nearby natural bottom compared to sites on the back-filled pipeline trench.
British Dictionary definitions for hydroid

hydroid

/ˈhaɪdrɔɪd/
adjective
1.
of or relating to the Hydroida, an order of colonial hydrozoan coelenterates that have the polyp phase dominant
2.
(of coelenterate colonies or individuals) having or consisting of hydra-like polyps
noun
3.
a hydroid colony or individual
Word Origin
C19: from hydra + -oid
hydroid in Science
hydroid
  (hī'droid')   
Any of numerous, usually colonial marine coelenterates of the order Hydroida, having a polyp rather than a medusoid form as the dominant stage of the life cycle. Hydroids have a simple cylindrical body with a mouthlike opening surrounded by tentacles. Most species form colonies with individual hydroids branching off from a common hollow tube that is probably used to share ingested food. The young develop from eggs or from buds. The most well-known hydroids are the hydras (genus Hydra), which are atypical in being both freshwater and solitary.