intransitive. To spread, widen out; to slope outwards towards the top. Also with out, off. to flanch up: to slope inwards towards the top…

intransitive. To widen out. Also, with out.

intransitive. To open or spread outwards, as the sides of a bowl, a skirt, the mouth of a horn.

intransitive with out. To spread out like the mouth of a bell. So belled-out adj.