Webster's 1828 Dictionary
ALLANTOIS, ALLANTOID
n.[Gr. a sausage, and form. ] A thin membrane, situated between the chorion and amnios in quadrupeds, and forming one of the membranes which invest the fetus in those animals.
Webster's 1913 Dictionary
ALLANTOIS; ALLANTOID
ALLANTOIS; ALLANTOID Al *lan "to *is, Al *lan "toid, } n.. (Anat. )
Defn: A membranous appendage of the embryos of mammals, birds, and reptiles, -- in mammals serving to connect the fetus with the parent; the urinary vesicle.
New American Oxford Dictionary
allantois
al lan to is |əˈlantō -is əˈlæntəwəs | ▶noun ( pl. allantoides |ˌalənˈtō -idēz | ) the fetal membrane lying below the chorion in many vertebrates, formed as an outgrowth of the embryo's gut. In birds and reptiles it grows to surround the embryo; in eutherian mammals it forms part of the placenta. DERIVATIVES al lan to ic |ˌalənˈtō -ik |adjective, al lan toid |-toid |adjective ORIGIN mid 17th cent.: modern Latin, based on Greek allantoeidēs ‘sausage-shaped. ’
Oxford Dictionary
allantois
allantois |əˈlantəʊɪs | ▶noun ( pl. allantoides |-ɪdiːz | ) the fetal membrane lying below the chorion in many vertebrates, formed as an outgrowth of the embryo's gut. In birds and reptiles it grows to surround the embryo; in eutherian mammals it forms part of the placenta. DERIVATIVES allantoic |alənˈtəʊɪk |adjective, allantoid |əˈlantɔɪd |adjective ORIGIN mid 17th cent.: modern Latin, based on Greek allantoeidēs ‘sausage-shaped ’.
Duden Dictionary
Allantois
Al lan to is Substantiv, feminin , die |All a ntois |die Allantois; Genitiv: der Allantois Urharnsack embryonales Organ der Reptilien, Vögel und Säugetiere einschließlich des Menschen
The Wordsmith Dictionary