woven mat; sedge mat; straw mat
A mat woven from plant materials such as sedge or hay, used for covering, sitting, or drying things.
The fisherman spread a woven mat on the boat and rested.
In old houses, woven mats were sometimes used on roofs.
rush-thatched house
Standard kanji for a woven mat, especially one made of sedge or straw.
Alternate kanji, less common; originally referred to a bamboo mat or awning.
The word とま is of native Japanese origin. The kanji 苫 is a phono-semantic compound with 艹 (plant) and 占 (to occupy), suggesting a mat that covers or occupies a space. The alternate kanji 篷 originally referred to a bamboo mat or awning, and its use for とま is an extension.