His eyes had already the keenness of a falcon, and so straight and strong he grew that the heart of King Alf was filled with joy.
But his added weight had evidently done nothing to his keenness of mind.
He opened up his heart to Martin, showed with what keenness and with what enormous planning he had made the store.
The expression of keenness on a deal was not characteristic of him alone.
Page 175: "observavation" changed to "observation" (In old bears curiosity is accompanied with a keenness of observation).
The sheriff was impressed by the other's keenness of observation.
But afterwards he continued to look at me in silence with a keenness and curiosity I did not understand.
When he was shown into the lawyer's room, he exhibited a greater air of keenness than usual.
His portrait exhibits a face in which quickness and keenness of intellect are strongly marked.
Of his keenness of observation take the following illustration.
c.1200, from Old English cene "bold brave," later "clever, wise," from Proto-Germanic *kan- "be able to" (see can). Original prehistoric senses seem to have been both "brave" and "skilled;" cognate with Old Norse kænn "skillful, wise," Middle Dutch coene "bold," Dutch koen, Old High German kuon "pugnacious, strong," German kühn "bold, daring." Sense of "eager" is from mid-14c. The meaning "sharp" is peculiar to English: of blades and edges early 13c., of sounds c.1400, of eyesight c.1720. A popular word of approval in teenager and student slang from c.1900.
"lament," 1811, from Irish caoinim "I weep, wail, lament," from Old Irish coinim "I wail." Related: Keened; keening. As a noun from 1830.