Definition of "callow"

Then there was a little Chinese in full azure costume, with long gesticulating arms, and large callow head, who pertinaciously threw in his squeaky plea for Confucius in the most unsyntactical French.

1878, Alfred Egmont Hake, Paris Originals: With Twenty Etchings, page 25

In fact many of our fresh water fish are somewhat Chinese in their tastes, for I have frequently used, with great success, the callow and hairless young of field-mice as bait for mascalonge, pike, pickerel, bass and sheep'shead, […]

1883, William Charles Harris, The American Angler, volume 3, page 20

[…] while its congener of the land (A. agrestis) breeds in myriads over the adjoining meadows, hollowing out its nest just enough under the sward for its hairless callow young to be clear of the dangerous scythe-blade.

1890, Mayne Reid, The Naturalist in Siluria, page 5

There was a sense abroad as he spoke that the world was rocking together to great music, and this callow-headed professor by the table had caught a note of it.

1916, The Living Age, volume 290, page 24

This time it held a callow-headed baby in a pink frock.

1944, Chambers's Journal, page 225

These hands were marked of hard work and yet soft enough to tenderly hold the baby's little callow head.

2011, Altea, Happiness Was a Red Cadillac, page 17

And in the leafy summit spy'd a nest, / Which, o'er the callow young, a sparrow pressed.

1717, John Dryden, “Book XII”, in Ovid’s Metamorphoses in Fifteen Books. […], London: […] Jacob Tonson, […]

When first born it is indeed more feeble and incapable of voluntary action of any kind than a callow bird, blind and hairless, covered with a delicate pink skin, […]

1883, Arthur Nicols, Zoological Notes on the Structure, Affinities, Habits, and Mental Faculties of Wild and Domestic Animals, page 104

The restless scrolling, the clammy self-reproach afterwards … we could recognise that as addiction quite easily, but the mathematical mechanism for having created it makes horrible sense (Lanier isn’t that interested in culprits, though he finds all of Silicon Valley pretty callow).

2018 May 30, Zoe Williams, “Ten Arguments for Deleting Your Social Media Accounts Right Now by Jaron Lanier – review”, in The Guardian‎

Barça had frozen. Alexander-Arnold saw it, caught Divok Origi’s eyes and pinged the perfect cross for a double-take of a winning goal. This was a 20-year-old local lad, product of down the road, out-thinking Barcelona, making them look like callow, pigeon-chested schoolboys.

2019 May 8, Barney Ronay, “Liverpool’s waves of red fury and recklessness end in joyous bedlam”, in The Guardian‎