What is the origin of 'sleep tight'?
Read moreOne of the mysteries of the English language finally explained.
Treated as plural. Polygons of patterned ground.
Early 20th century; earliest use found in The Botanical Gazette. From German Polygonboden, lit. ‘polygon ground’ (1902 or earlier in the source reviewed in quot. 1902; from Polygon + Boden, after Swedish rutmark chequered ground).