From Longman Dictionary of Contemporary Englishhatpinhat‧pin /ˈhætˌpɪn/ noun [countable] DCCa long pin that is used to make a woman’s hat stay on her head
Examples from the Corpus
hatpin• He picked up my white cloth hat and fastened it to my hair with a hatpin.• Her black straw hat, secured by a beaded hatpin, had seen its best days long ago.• He leaned over her, removed her cheap hatpin and her old straw hat.• Her black velvet hat was slightly askew, held in that position by her hatpin. 