There are multiple definitions:

1. metered-dose inhaler(English)

   • DPI, HFA, LABA, pMDI, BA-pMDI
   • Respiratory system, Therapeutic approaches
   • https://doi.org…46143-6.00020-8
   • https://doi.org…406.2014.972510

2. manic-depressive illness(English)

   • see also cyclothymia
   • Psychology, Depression

3. mental development index(English)

   • a composite measure of nonverbal cognitive and language development
   • PDI, BSID
   • Mental health
   • https://www.nat…pdf?origin=ppub

4. mean decrease in impurity(English)

   • calculates each feature importance as the sum over the number of splits that include the feature, proportionally to the number of samples it splits
   • Machine learning
   • https://rdrr.io…er/man/MDI.html

5. Major Depression Inventory(English)

   • DSM
   • Depression

6. multiple daily injections(English)

   • CSII, rt-CGM, SMBG
   • Insulin
   • https://doi.org…201209040-00508

7. metabolism-dependent inhibitor(English)

   • CYP2C19, HLM, PPI
   • Metabolism
   • https://doi.org…/dmd.111.041293