Traditionally your rank in life stated where you sat at the dinner table. Since Lydia was the first Bennet daughter to be married, she took Jane's spot on her father's right. A married women came before the eldest daughters and the older daughter was superior than the younger children in rank. (John Trusler, The Honours of the Table, 4)

"A light two-wheeled carriage, usually drawn by two horses abreast" (OED).

A breakfast room was designed to be in close proximity to the kitchen. This room was designed to offer a relaxing and comfortable space to have the first meal of the day.

www.hunker.com/13413432/dining-room-vs-breakfast-room.

Hackneys, or public carriages for hire, made their first significant appearance in the early 17th century. By 1694, this method of transportation was very popular so the Hackney Coach Commission was established in London.

https://janeaustensworld.wordpress.com/tag/regency-transportation/

"Of persons (or their attributes): Uncivilized, savage; uncultured, rude; also, not accepting, or resisting, the constituted government; rebellious. Sometimes with implication of sense" (OED).

"A chamber or hall immediately between the entrance-door and the interior of a building or house, to which it gives admittance; an ante-chamber, entrance-hall, or lobby" (OED).