Definition of Ld in English:

Ld

  • Lord.

    ‘Ld Lothian’

Definition of LD in English:

LD

  • 1North American Learning disability (or disabled).

  • 2Lethal dose (of a toxic compound, drug, or pathogen). It is usually written with a following numeral indicating the percentage of a group of animals or cultured cells or microorganisms killed by such a dose, typically standardized at 50 per cent (LD50).

    • ‘The LD50 test does not account for drug interactions, and is therefore of little use in such cases.’
    • ‘You may obtain the LD50 number by contacting the manufacturer at the phone number listed on the pesticide label.’
    • ‘The only figure of real interest is the subcutaneous LD50 as few snakes can ever achieve anything other than that.’
    • ‘That's all well and good, but how do you attach significance to the LD50 numbers that you might find?’
    • ‘Special calculations are used when translating animal LD50 values to possible lethal dose values for humans.’