One liner definitions of Karma, Akarma and Vikarma

Actions that are performed in terms of one’s prescribed duties, as mentioned in the revealed scriptures, are called karma.

Actions that free one from the cycle of birth and death are called akarma.

And actions that are performed through the misuse of one’s freedom and that direct one to the lower life forms are called vikarma.

– Srila Prabhupada, Sri Isopanishad Mantra 2