深入

深入	shēn rù	to penetrate deeply / thorough
深	shēn	old variant of 深
深	shēn	deep (lit. and fig.)
入	rù	to enter; to go into / to join; to become a member of / (bound form) to conform to (as in 入时) / abbr. for 入声 / (on product packaging, after {number n} + {classifier}) containing (n pieces) (from Japanese 入 "iri")