Outwinter is a term often used in agriculture and animal husbandry to describe the practice of keeping livestock outdoors during winter months. There are several synonyms that can be used in place of "outwinter" to convey a similar meaning. One such synonym is "overwinter", which suggests the process of surviving winter conditions. Another alternative is "wintering out", which refers to the act of enduring the winter season. Additionally, "winter grazing" can be employed to describe the practice of allowing animals to graze freely in outdoor areas throughout winter. Overall, these synonyms serve as useful alternatives to the term "outwinter", while maintaining the essence of the practice.