■ noun a type of ink used to produce writing that cannot be seen until the paper is heated or otherwise treated.
INVISIBLE INK
Meaning of INVISIBLE INK in English
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004
■ noun a type of ink used to produce writing that cannot be seen until the paper is heated or otherwise treated.
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004