Other forms: thorns
A thorn is the sharp spike growing out of a plant's stem — the thing that catches your finger when you grab a rose too fast. Blackberry bushes bristle with them, and so does a hawthorn hedge.
The adjective is thorny: a thorny hedge, and also a thorny problem, one with sharp bits wherever you touch it. Figuratively a thorn is a small lasting irritation, which is why 'a thorn in my side' is the colleague who queries everything. Thorn is also the name of the Old English letter þ, which wrote the sound at the start of 'thin', and you meet it faked as a Y in 'ye olde shoppe'. Botanists draw a line the rest of us ignore: a true thorn is a modified stem, so a rose strictly has prickles. Nobody outside botany says prickle, and nobody needs to worry about it.
1nounthornA sharp point growing on the stem or branch of a plant.
“A thorn went straight through her gardening glove.”
2nounletterThe Old English letter þ, used for the 'th' sound.
“Old manuscripts write 'the' with a thorn and a small e above it.”
thorn is a plant part.
Also accepted in games: thorns
Thorn is one of the oldest words in the language and has barely changed shape. Old English þorn goes back through Proto-Germanic *þurnaz to Proto-Indo-European *tr̥nós, from a root meaning 'stiff'. Its cousins stand all over northern Europe — German Dorn, Dutch doorn, Swedish törne — and further out a Sanskrit relative means simply 'grass'.
Proto-Indo-European
*tr̥nós
Proto-Germanic
*þurnaz
Proto-West Germanic
*þorn
Old English
þorn
Middle English
thorn
English, today
thorn
Built from
From Middle English thorn, þorn, from Old English þorn, from Proto-West Germanic þorn, from Proto-Germanic þurnaz, from Proto-Indo-European tr̥nós, from (s)ter- (“stiff”). 2 Near cognates include West Frisian toarn, Low German Doorn, Dutch doorn, German Dorn, Danish - and Norwegian - torn, Swedish torn, törne, Gothic 𐌸𐌰𐌿𐍂𐌽𐌿𐍃. Further cognates include cu трънъ (“thorn”), Russian тёрн, Polish cierń, bsh taňi, tai (“thorn”), Sanskrit तृण (“grass”).
Etymology from Wiktionary, CC BY-SA
Practised in Nature & Weather, Trees & Flowers