Hěnduō zì de zìyì gǔjīn bùtóng, dú gǔwén shí yào tèbié zhùyì.
Many characters have different meanings in ancient and modern Chinese, so take special care when reading classical texts.
Tips
usage
Knowing a character means knowing its 字形 "shape", 字音 "sound" and 字义 "meaning". For a word the term is 词义, and in conversation people simply ask about its 意思.