Dissyllabification (n.)
definition: A forming into two syllables.

Dissyllabification is an 18 letter word that begins with a D and ends in an N

Establishmentarian (n.)
definition: One who regards the Church primarily as an establishment formed by the State, and overlooks its intrinsic spiritual character.

Establishmentarian is an 18 letter word that begins with an E and ends in an N

Fres'nel' lan'tern
definition: A lantern having a lamp surrounded by a hollow cylindrical Fresnel lens.

Fres'nel' lan'tern is an 18 letter word that begins with a F and ends in an N

Glasstonbury thorn
definition: A variety of the common hawthorn.

Glasstonbury thorn is an 18 letter word that begins with a G and ends in an N

Iatromathematician (n.)
definition: One of a school of physicians in Italy
About the middle of the 17th century who tried to apply the laws of mechanics and mathematics to the human body and hence were eager student of anatomy; -- opposed to the iatrochemists.
Iatromathematician is an 18 letter word that begins with an I and ends in an N

Intercommunication (n.)
definition: Mutual communication.

Intercommunication is an 18 letter word that begins with an I and ends in an N

Naleadministration (n.)
definition: Maladministration.

Naleadministration is an 18 letter word that begins with an N and ends in an N

Self-contradiction (n.)
definition: The act of contradicting one's self or itself; repugnancy in conceptions or in terms; a proposition consisting of two members
One of which contradicts the other; as to be and not to be at the same time is a self-contradiction.
Self-contradiction is an 18 letter word that begins with an S and ends in an N

Self-determination (n.)
definition: Determination by one's self; or
Determination of one's acts or states without the necessitating force of motives; -- applied to the voluntary or activity.
Self-determination is an 18 letter word that begins with an S and ends in an N

Self-fertilization (n.)
definition: The fertilization of a flower by pollen from the same flower and without outer aid; autogamy.

Self-fertilization is an 18 letter word that begins with an S and ends in an N

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