LT是light的缩写。
light：n.光；光线；光亮；(具有某种颜色和特性的)光；发光体；光源；(尤指)电灯
相关介绍You are probably well enough to take a little light exercise.
（图片来自网络侵删）
你恢复得不错，大概可以做些轻微的运动了。
Recent research has thrown new light on the causes of the disease.
最近的研究可以使人进一步了解导致这种疾病的原因。
He came up to me and asked for a light.
他走到我跟前来借火。
