The phrase "twin size" refers to a type of bed or mattress that is smaller than a full-size bed but larger than a crib bed. It is designed for one person and is commonly found in guest rooms or for kids. Full definition
Just off the entrance of the villa is the second master bedroom with twin size beds that can be converted to a king size bed upon request. (waikoloavacationrentals.com)
It was a family experience as we watched with eyes wide, the small flat package turn into the most comfortable twin size mattress we have ever purchased. (5littlemonkeysbed.com)
It offers a full - size bed on the bottom with an additional twin size bed on top. (wyndhamvacationrentals.com)