Phrases starting with the letter: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Previous word: allantoin
Next word: allay
Definition of: allantois
(ə·lan′tō·is) noun
A membranous, fluid-filled sac that develops from the hindgut in the embryos of reptiles, birds, and mammals. [< NL <allantoides <GK. See ALLANTOID.]
—al·lan·to·ic (al′ən·tō′ik) adjective
Comment about this word, ask questions, or add new information about this topic: