1. Lancet arches are pointed arches over long openings. They were grouped together with three or five lancet arches together being common.
2. Flying buttresses are wall supports that have a masonry block at the ground and an arch that connects the block to the wall.
3. Gargoyles are the creature serving as actual water spout. In architecture their functions serve as decorations.
4. Barrel vaults are vaults forming in a half cylinder, commonly seen in many ancient and modern structures.
5. Migration Period art is the artwork of germanic people during the migration period.
Hope this helps :)