"Lapse of lingy"
Amy means to say lapsus linguae, which is Latin for “slip of the tongue”
'Aisy
Without hardship; a dialectic shortening of "easy"
Abominable
Detestable, awful
Aristocratic
Belonging to a high social or political class; of the nobility
Assiduity
Persistent and diligent effort
Belladonna
A medicine made of deadly nightshade, used as a home remedy for scarlet fever
Benevolence
Inclination to do good and help others
Blancmange
Dessert similar to pudding made with cream and sugar and a thickener such as cornstarch
Capricious
Impulsive and fickle, likely to change based on chance rather than reason
Chaplain
A priest, pastor, or other clergy member assigned to an official group, such as a military unit
Conservatory
A greenhouse for growing flowers
Coquetry
Playful, flirtatious behavior intended to arouse interest
Cravat
Neckband; forerunner of the modern necktie
Droll
Comical in a whimsical manner
Dudgeon
Intense indignation
Ennui
Intense boredom and listlessness
Fashion-plate
A picture advertising the latest fashions
Governess
A woman employed to watch and teach children in a private home; a nanny
Indolent
Habitually lazy and procrastinating
Libel
A written insult
Out
In this context, being "out" means having officially entered into society. "Coming out" was sometimes celebrated with parties similar to a debutante ball.
Panacea
Cure-all
Penitent
Regretful
Propriety
Proper behavior; in the case of Mr. Brooke and Kate Vaughn to "play propriety" at Camp Laurence, this means chaperone
Tranquility
An untroubled and peaceful state
Truckle
Yield to out of weakness
Vortex
A fast-moving spiral, such as a whirlpool