Webster's 1828 Dictionary
PERTNESS
n.Briskness; smartness. 1. Sauciness; forward promptness or boldness; implying less than effrontery or impudence.
Pertness and ignorance may ask a question in three lines, which it will cost learning and ingenuity thirty pages to answer.
2. Petty liveliness; sprightliness without force, dignity or solidity.
There is in Shaftsbury's works a lively pertness and a parade of literature.
Webster's 1913 Dictionary
PERTNESS
PERTNESS Pert "ness, n.
Defn: The quality or state of being pert.
New American Oxford Dictionary
pertness
pert ness |ˈpərtnis ˈpərtnɪs | ▶noun 1 the quality of being attractively neat and jaunty. 2 impudence; cheek.
Oxford Dictionary
pertness
pert |ness |ˈpəːtnəs | ▶noun [ mass noun ] 1 the quality of being attractively small and well shaped. 2 impudence; cheek.
Oxford Thesaurus
pertness
pertness noun a Liverpool-born lass renowned for pertness: impudence, impertinence, cheek, cheekiness, sauciness, effrontery, irreverence, insolence, disrespect, disrespectfulness, flippancy, presumption, presumptuousness, audacity, audaciousness, boldness, brazenness, forwardness, cockiness, shamelessness; informal mouth, neck, brass neck, nerve; Brit. informal sauce; Scottish informal snash; N. Amer. informal sassiness, sass, chutzpah, a smart mouth; archaic malapertness; rare procacity.