The idiom "Tianma Xingkong" originally refers to the divine horse.
天马行空
tiān mǎ xíng kōng
Explanation of Tianma: divine horse. The Pegasus gallops very fast, as if it is flying in the air. Metaphorical poetry is bold and bold. It also refers to people who are impetuous and unsteady.
Sourced from "Preface to the Collection of Poems of Sa Tianxi" by Liu Tingzhen of the Yuan Dynasty: "The reason why it is deified and transcends all other forms is probably like a horse flying in the sky with extraordinary steps."
Structure subject-predicate form.
Usage is used to describe quick thinking; bold and unrestrained. Generally used as predicate and attributive.
Correct pronunciation; cannot be read as "hánɡ"; empty; cannot be read as "kònɡ".
Synonyms: free and easy, flying and flying
Antonym: restrained
Example: This young calligrapher is in full view of the public; he is free and easy; just like~.