thư

Etymology 1
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Noun

 * 1)  a

Affix

 * 1)  a

Usage notes
In Chinese, ambiguously means "book", "document" or "letter". In Vietnamese, the senses of "book" and "document" are only fossilized and not productive. The free noun only means "letter". For the free noun meaning "book", use instead.

Etymology 2
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Adjective

 * 1)  inactive, idle, unoccupied, free

Adverb

 * 1) leisurely, unhurriedly, deliberately, at leisure