Wikipedia:

Chordate | Chordates | Chordata

Summary:

animals which are either vertebrates or one of several closely related invertebrates. They are united by having, for at least some period of their life cycle, a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle, and a post-anal ...  (40 of 3433 words, 7 images)

Link:

http://en.wikipedia.org/wiki/Chordate  [cite]

Britannica:

chordate

Summary:

any member of the phylum Chordata, which includes the vertebrates, the most highly evolved animals, as well as two other subphyla—the tunicates and ...  (24 of 104 words)

Link:

http://www.britannica.com/EBchecked/topic/114462/chordate  [cite]

Encarta:

chordate | chordates [plural]

Summary:

an animal that at some stage in its development has a main dorsal nerve cord, a skeletal rod notochord, and gill slits, including all vertebrates and ...  (26 of 60 words, 1 etymology, pronunciation)

Link:

http://encarta.msn.com/dictionary 1861597023/definition.html  [cite]

Merriam-Webster:

chordate

Summary:

any of a phylum (Chordata) of animals having at least at some stage of development a notochord, dorsally situated central nervous system, and gill ...  (24 of 49 words, 1 etymology, pronunciation)

Link:

http://www.merriam-webster.com/dictionary/chordate  [cite]

Wiktionary:

chordate | chordates [plural]

Summary:

A member of the phylum Chordata; numerous animals having a notochord at some stage of their development; in vertebrates this develops into the spine | Of such animals.  (27 of 38 words, 2 senses, pronunciation)

Link:

http://en.wiktionary.org/wiki/chordate  [cite]

Random House:

chordate

Summary:

[zoology] | belonging or pertaining to the phylum Chordata, comprising the true vertebrates and those animals having a notochord, as the lancelets and ...  (22 of 32 words, 3 senses, pronunciation)

Link:

http://dictionary.infoplease.com/chordate  [cite]