Final answer:
Euthyroid means the patient's thyroid hormone levels are within normal limits.
Step-by-step explanation:
The term “euthyroid” refers to the state in which a patient's thyroid hormone levels are within normal limits. In this case, the patient's levothyroxine medication has successfully brought their thyroid hormone levels into the normal range. This means that the patient's thyroid gland is functioning properly and they are not experiencing hyperthyroidism or hypothyroidism.