These are the words autumn and winter associated with a hyphen. They are usually used to indicate a 6-month period that coincides with those seasons; often clarifying the hemisphere.
AUTUMN-WINTER season of 6 continuous months comprising the seasons dd autumn and winter. Widely used term to advertise appropriate fashion and costumes and . that can be used during those months.
Cold season binomial. Time of year or semester where lower temperatures occur. Season of the year from September to February.