Final answer:
The likely reason for Lord Randall's death in the ballad is poisoning, as revealed through a dialogue suggesting he was given tainted food by his lover.
Step-by-step explanation:
In the ballad "Lord Randall", the likely reason for Lord Randall's death is poisoning. The story unfolds through a dialogue between Lord Randall and his mother, where he says that he is 'weary from hunting' and has been dining with his true love. As the conversation progresses, details emerge that suggest he has been poisoned, likely by the food given to him by his love.
The refrain "I fain would lie down" suggests growing fatigue which is a common symptom of poisoning. Moreover, the ballad ends with a chilling revelation, where he tells his mother to prepare his deathbed, indicating his impending demise.
While drowning, old age, and illness are common causes of death, within the context of this ballad, the evidence strongly points to poisoning, especially considering the narrative's focus on the meal he had with his lover and the symptoms displayed thereafter.