get-well card; sympathy letter
A letter or card sent to someone who is ill or has suffered a misfortune, expressing concern or sympathy.
I sent a get-well card to my friend who is in the hospital.
Thank you for the sympathy letter.
Compound of 見舞い (みまい, 'visiting someone who is ill or in trouble') + 状 (じょう, 'letter, card').