From Longman Dictionary of Contemporary Englishslingbacksling‧back /ˈslɪŋbæk/ noun [countable] DCCa woman’s shoe that is open at the back and has a narrow band going around the heel
Examples from the Corpus
slingback• Was getting down the same as getting up and could you do it in platforms and slingbacks?• Miss Selfridge, kitten-heeled slingbacks with elastic front, £29.99. 