noun
: a constant of radioactivity represented by λ in the equation I t . I o e - λ, where I o is initial activity, I t activity after time t, and e the natural logarithmic base
noun
: a constant of radioactivity represented by λ in the equation I t . I o e - λ, where I o is initial activity, I t activity after time t, and e the natural logarithmic base
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012