Acanthopterygious (a.)
definition: Having fins in which the rays are hard and spinelike; spiny-finned.

Acanthopterygious is a 17 letter word that begins with an A and ends in an S

Acromonogrammatic (a.)
definition: Having each verse begin with the same letter as that with which the preceding verse ends.

Acromonogrammatic is a 17 letter word that begins with an A and ends in a C

Addison's disease
definition: A morbid condition causing a peculiar brownish discoloration of the skin
And thought at one time to be due to disease of the suprarenal capsules (two flat triangular bodies covering the upper part of the kidneys) but now known not to be dependent upon this causes exclusively. It is usually fatal.
Addison's disease is a 17 letter word that begins with an A and ends in an E

Administratorship (n.)
definition: The position or office of an administrator.

Administratorship is a 17 letter word that begins with an A and ends in a P

Aestho-physiology (n.)
definition: The science of sensation in relation to nervous action.

Aestho-physiology is a 17 letter word that begins with an A and ends in a Y

Amphitheatrically (ad)
definition: In the form or manner of an amphitheater.

Amphitheatrically is a 17 letter word that begins with an A and ends in a Y

Angiomonospermous (a.)
definition: Producing one seed only in a seed pod.

Angiomonospermous is a 17 letter word that begins with an A and ends in an S

Anthropomorphitic (a.)
definition: to anthropomorphism.

Anthropomorphitic is a 17 letter word that begins with an A and ends in a C

Anthropomorphosis (n.)
definition: Transformation into the form of a human being.

Anthropomorphosis is a 17 letter word that begins with an A and ends in an S

Anthropophaginian (n.)
definition: One who east human flesh.

Anthropophaginian is a 17 letter word that begins with an A and ends in an N

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