A box-shaped musical instrument with means of keys and buttons, whose tones are generated by play of the wind from a squeezed bellows upon free metallic reeds.

(graphical user interface) A vertical list of items that can be individually expanded and collapsed to reveal their contents.

(figurative) (Can we verify(+) this sense?) A set of items (concepts, links, or otherwise) that can be packed and unpacked cognitively, or their representation as a set of virtual objects.

(transitive, intransitive) To fold up, in the manner of an accordion