This is the 2653rd most frequent Japanese word.
枕
"枕" means "pillow."
枕 is used literally to refer to a pillow, an object used for sleeping.
枕が柔らかくて、よく眠れました。
The pillow was soft, so I slept well.
枕 is used metaphorically to indicate the area near the pillow, creating imagery related to sleeping arrangements.
彼はいつも枕元に大事な本を置いています。
He always places an important book near his pillow.
枕 is part of the compound 枕詞, referring to a stylistic device in traditional Japanese poetry.