EtoL

embattled molding - having indentions like those of a battlement.
 

fan tracery vaulting - a system of ceiling vaulting with all ribs having the same curve, resembling the folds of a fan. 
 

finial - the top or finishing stone of a pinnacle. 
 

flying buttress - a buttress arched over at the top to engage with a main wall. A principal feature of Gothic architecture, lending strength and solidity to the main structure.

gargoyle - a spout  usually carved in the shape of an animal or demon,  and connected to a gutter for throwing rain water from the roof of a building.
 

green man - an ancient symbol of man's deep connection to nature; a decorative Gothic carving characterized by a human face sprouting foliage.

grotesque - a carving usually of a demon, dragon, or half human/half animal, serving no utilitarian purpose. Often confused with gargoyles.

jambs - the stones forming the side of a door or window.
 

jamb figures - located on either side of the west front door; the first carved figures a visitor meets on a visit to a Gothic cathedral.  Traditionally depicting Old Testament prophets, or martyred saints.
 

keystone - the central stone of an arch that locks the other units in place. See voussoirs.
 

Lancet arch - a Gothic pointed arch usually applied to long, narrow windows. See arch.
 

Lady chapel - the easternmost chapel of a cathedral, intended for quiet contemplation and the occasional special service.