mal-

1.
a combining form meaning “bad,” “wrongful,” “ill,” occurring originally in loanwords from French (malapert); on this model, used in the formation of other words (malfunction; malcontent).
Compare male-.
Origin
Middle English < Old French, representing mal adv. (< Latin male badly, ill) and adj. (< Latin malus bad)
British Dictionary definitions for mal-

mal-

combining form
1.
bad or badly; wrong or wrongly; imperfect or defective: maladjusted, malfunction
Word Origin
Old French, from Latin malus bad, male badly
Word Origin and History for mal-

word-forming element meaning "bad, badly, ill, poorly, wrong, wrongly," from French mal (adv.), from Old French mal (adj., adv.) "evil, ill, wrong, wrongly" (9c.), from Latin male (adv.) "badly," or malus (adj.) "bad, evil" (fem. mala, neuter malum), of unknown origin, perhaps related to Avestan mairiia "treacherous." Most Modern English words with this prefix are 19c. coinages.

mal- in Medicine

mal- pref.

  1. Bad; badly: malpractice.

  2. Abnormal; abnormally: malformation.