Millinery means hats: posh hats!
(The dictionary says millinery also covers the trimmings and anything else sold by a hat-maker, but sadly there aren't many hat-makers around nowadays.)
It used to be illegal for a man to go out without a hat in England (that was in the time of the first Queen Elizabeth, and was intended to support the wool trade) but now wearing a hat is entirely optional, though still a source of joy to all.
Now, as I've already said, millinery usually describes rather posh hats, but for spotting purposes I don't see why any hat shouldn't count.
What is the function of the first hat you can spot?
To keep the head warm?
To keep off the weather?
photo by Hex
To keep safe?
Photo by CEphoto, Uwe Aranas
To show membership of some profession?
To display fashion and/or wealth?
Illustration by James Gillray
To show your brave history and spiritual wisdom?
Or...well, actually I'm not sure about this one:
photo of Georgian dancer by George Kvizhinadze
...these animals called humans really are quite odd, aren't they?
Spot the Frippet: millinery. All posh hats come from Milan! The word used to be Milaner, a place in the 1500s famous for its fancy goods,