kill, slay, murder, assassinate, dispatch, execute mean to deprive of life.

kill merely states the fact of death caused by an agency in any manner.

slay is a chiefly literary term implying deliberateness and violence but not necessarily motive.

murder specifically implies stealth and motive and premeditation and therefore full moral responsibility.

assassinate applies to deliberate killing openly or secretly often for political motives.

dispatch stresses quickness and directness in putting to death.

execute stresses putting to death as a legal penalty.

perform, execute, discharge, accomplish, achieve, effect, fulfill mean to carry out or into effect.

perform implies action that follows established patterns or procedures or fulfills agreed-upon requirements and often connotes special skill.

execute stresses the carrying out of what exists in plan or in intent.

discharge implies execution and completion of appointed duties or tasks.

accomplish stresses the successful completion of a process rather than the means of carrying it out.

achieve adds to accomplish the implication of conquered difficulties.

effect adds to achieve an emphasis on the inherent force in the agent capable of surmounting obstacles.

fulfill implies a complete realization of ends or possibilities.