gallop

A horse  working hard  also provides the pronunciation

Components
敄 sound,meaning component

  Sound Meaning component

  

to put forth effort

馬 meaning component

  Meaning component

  

horse

Evolution

騖 Seal script Shuowen (~100 AD)

Seal script

Shuowen (~100 AD)
騖 Clerical script Western Han dynasty (202 BC-9 AD)

Clerical script

Western Han dynasty (202 BC-9 AD)
騖 Clerical script Western Han dynasty (202 BC-9 AD)

Clerical script

Western Han dynasty (202 BC-9 AD)
騖 Regular script Modern

Regular script

Modern
Definitions

() 

gallop; rush about; pursue, run; fast; greedy; run rapidly

Most common words with 騖
Freq.
Word
Meaning

fast

好高骛远

to aim too high