The outer portion of a nut (as opposed to the threads inside).
1881, Gardeners Chronicle & New Horticulturist, page 271:
The boards we use are attached to the permanent stone copings by bolts and nuts 4 feet apart ; iron bands, which are used to strengthen the boards, afford firm hold for the nut-heads.
1879, United States Patent Office, Specifications and Drawings of Patents Issued from the U.S. Patent Office, page 129:
In such a device the riveting may be effected with proper riveting-tools, and the nut-head afterward screwed on.
1897, American Institute of Mining Engineers, Transactions - Volume 26, page 1018:
The machine is commonly rated at 800,000 pounds, but the last experiment approximating three-quarters of that amount ended by shearing off all the nut-heads at the recoil of the machine, and I found my labor was in vain.
2013, Lord Frederick J.D. Lugard, The Rise of Our East African Empire (1893), →ISBN:
The rails are bolted to these (the nut-heads being filed off if necessary), and the line thus forms a continuous whole.
A head (for a doll, puppet, etc.) made out of a nut.
1914, Gulian Lansing Morrill, To Hell and Back: My Trip to South America, page 20:
Speaking of nut-heads reminds me of the shrunken head trophies which head-hunters sell as souvenirs in the interior of Ecuador and of a specimen I later saw in La Paz.
1953, Lesley Gordon, Peepshow Into Paradise: A History of Children's Toys:
Dried plants make equally good raw material for toymakers, and vivid little personalities may be born of nut-heads with moss or corn silk hair, and peanuts or seedpods for feet; stitched leaf skirts and tiny bouquets of dried flowers, built on a foundation of pipe-cleaners and posed against a painted background.
Various species of weed found in New South Wales, Australia, including Lua error in Module:parameters at line 828: Parameter "noshow" is not used by this template. and Lua error in Module:parameters at line 828: Parameter "noshow" is not used by this template.
2011, Geoffrey McIver Cunningham, Plants of Western New South Wales, →ISBN, page 685:
Although dense stands of tall nut-heads are sometimes present after flooding, the plant more commonly occurs as scattered individuals.
1962, Harry Allen Smith, To Hell in a Handbasket, page 155:
They were tactful toward me, considerate of my feelings, and usually greeted me with encouraging remarks like, "Ain't you folks gone bankropt yit?" or "They's been some real nut-heads drift through here in my time but you birds take the cake."
"'That thing,'" the mother chuckled juicily at her daughter's clever turn of phrase. "That's what you call it a straight-jacket, dearyme. He's a nut-head, the poor poke."
Idiot.
1999, Culture Wars - Volume 19, page 36:
Addressing this cavalier Western attitude, Dr. Muniini K. Mulera warned "self-righteous moralists informed by hindsight" not to ask how anyone could be so gullible. "Labelling these people stupid nut-heads will not do," he wrote in the Monitor.
“I'm rinsing myhair in it, nut-head,” Julie said from beneath the swirl of dark blond hair. “Hand me my towel.” “Nut-head? You called your sweet little brother a nut-head?”