The word that has a meaning similar to "solitary" is "alone." Solitary and alone both refer to being by oneself or without companionship. In the context provided about polar bears, being solitary means that they prefer to live and travel alone, avoiding interactions with other polar bears for most of their lives.
In this context:
- "Calm" does not have a similar meaning to "solitary." Calm refers to a state of tranquility or peacefulness.
- "Large" and "strong" are descriptions of the physical attributes of polar bears and do not relate to the concept of being solitary.
Therefore, in this case, "alone" is the word that best aligns with the meaning of "solitary" as described in the text about polar bears.