coltishness

The quality of resembling a colt, especially:

The grand thing is to get rid of dogged sulks and coltishness—of that wayward, swerving, hesitating gait, which says, “Here’s my foot, and there’s my foot,” or “There is a lion in the street, I cannot go forth!”

“He hasn’t learned the art of taking it gracefully,” said the Major. “But he shouldn’t show temper. It’s a sign of coltishness that I don’t care for.” “Ah, well, he’s young,” said Daisy, with a sigh. “He’ll get over that.”

The quality of resembling a colt, especially:

Though only a year younger than Reuben, in the midst of the awkward age, his growing limbs quite lacked the coltishness of his brother’s.

1952, Agatha Christie (as Mary Westmacott), A Daughter’s a Daughter, New York: Dell, 1976, Book 2, Chapter 1, p. 111, Laura Whitstable was struck by her beauty. The awkward touch of coltishness had gone, she was now a remarkably attractive young woman, with a quite unusual loveliness of face and form.