freck
Not showing proper respect; impertinent, impudent.
archaic
Bold, brave, courageous.
archaic
"There was none to challenge him but old Keltie, and the carrier Auchtermuchty," replied Randal; "unlikely men to slay one of the frackest youths in Scotland of his years, and who was sure to have friends and partakers at no great distance."
Physically active and healthy; robust, vigorous.
archaic
[H]e's a freck aul' body at his age.
Often followed by for or to: eager to do something; also, quick to act when an opportunity arises; prompt.
archaic
["][T]his brother of thine, who is so frack, as the fellow called him, bears he the same wonderful likeness to thee as formerly?" / "If your Grace means in temper, you know whether I am so frack as the serving-man spoke him." / "Nay, thou art prompt enough in all reasonable conscience," replied the Queen; […]
Where it comes from
From Middle English frecch, frecche (“bold, brave; fierce; greedy, voracious”), frek (“bold, brave; fierce; eager, zealous; fast, quick; greedy (?)”), from Old English frec, fræc (“audacious, bold; greedy”) from Proto-West Germanic *frek (“greedy”), from Proto-Germanic *frekaz (“greedy”), from Proto-Indo-European *preg- (“to covet; to yearn”).
Adapted from the Wiktionary entry freck (CC BY-SA 4.0).