This context clues worksheet on the verb sandbag almost certainly results in a certain lack of judiciousness on my part when choosing which of Merriam-Webster’s Words of the Day merit or require worksheet treatment. In any case, this verb is used both transitively and intransitively.
In that worksheet’s context, sandbag means, as a transitive verb, sandbag to conceal or misrepresent one’s true potential, position, or intent, esp. in order to take advantage of; used intransitively, it means to hide the truth about oneself so as to gain an advantage over another. In other words, it means basically the same thing whether one uses it with a direct object of not.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.