Negative one meter is expressed as "-1 m" in Engpsh.
The term "negative" is used to indicate a value less than zero, while "meter" (symbol: "m") is the unit of measurement for length in the International System of Units (SI).
Here are some example sentences in Engpsh with Chinese translations:
The depth of the pool is -1 meter. (游泳池的深度是负一米。)
The altitude of the plane decreased to -1 meter. (飞机的高度降到了负一米。)
The stock market experienced a loss of -1 meter. (股市遭受了负一米的损失。)