Refers to a pocket sewn on the inside of a garment, such as a jacket or coat. The word is somewhat dated; modern Japanese often uses 内ポケット (uchi poketto) instead.
There was an old letter in the inside pocket of my grandfather's coat.
The modern, more common term for 'inside pocket'. 内衣嚢 (うちかくし) is an older, rarely used word.
Obscure kanji spelling; the second character 嚢 is non-standard and may be a variant or error. The word is normally written in kana.
Alternate kanji spelling using 隠し (hidden), but still rare; kana is preferred.
The reading reflects 内隠し, “inside concealed pocket,” while 内衣嚢 denotes a pouch or pocket in the inside of a garment.