dunce hat
English
[edit]![](http://upload.wikimedia.org/wikipedia/commons/thumb/0/0f/Dunce_cap_from_LOC_3c04163u.png/170px-Dunce_cap_from_LOC_3c04163u.png)
Noun
[edit]dunce hat (plural dunce hats)
- (historical) A conical hat that a school pupil is made to wear to indicate that he/she is a dunce.
- (topology) The topological space obtained by identifying the sides comprising the boundary of a triangle, two sides with consistent orientation and the third with the reverse orientation.
Synonyms
[edit]- (both senses): dunce cap