malicious adj.

word-forming element of Latin origin 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), from Proto-Italic *malo-, from PIE *mol-o-, probably from PIE root *mel- (3) "false, bad, wrong."

Most Modern English words with this element are 19c. coinages. It generally implies imperfection or deficiency, but often it is simply negative (as in malfeasance, malcontent). It is equivalent to dys- and caco- of Greek origin and Germanic mis- (1).

c. 1300, "desire to hurt another, propensity to inflict injury or suffering, active ill-will," from Old French malice "ill will, spite, sinfulness, wickedness" (12c.), from Latin malitia "badness, ill will, spite," from malus "bad, unpleasant" (see mal-). In legal use, "a design or intention of doing mischief to another without justification or excuse" (1540s).

Actual malice, express malice, malice in fact, malice in which the intention includes a contemplation of some injury to be done.—Constructive malice, implied malice, imputed malice, malice in law, that which, irrespective of actual intent to injure, is attributed by the law to an injurious act intentionally done, without proper motive, as distinguished from actual malice, either proved or presumed. Malice aforethought, or malice prepense, actual malice particularly in case of homicide. [Century Dictionary]