A strategem refers to a tactic or approach used for achieving a goal. However, there are several synonyms for this word that can be used interchangeably. One of them is ploy, which is a clever and often sneaky way of achieving one's objective. A maneuver is another synonym that refers to a skillful and calculated move made for accomplishing a specific outcome. A scheme is yet another synonym that refers to a plan or plot designed to achieve a particular end. Finally, a ruse is a synonym that refers to a trick or deception used to achieve a goal. Overall, these synonyms effectively capture the essence of a strategem, which is a calculated and cunning way of achieving one's aims.