wei3 can be seen to have the components where the first denotes 'lower part of the body' and the second is the character mao meaning 'hair'. By extension it also means 'the remaining part'.
ma3wei3 means 'horse tail'
ma3 in its original script is which is a clear graphical representation of a horse with long flowing mane.
wei3zhui1 means 'hot on the trail of' and literally translates as 'tail'-'chase'.
has two components .
The first component means 'distance' and the second component denotes 'a
mound'. Curiously, although its modern meaning is 'chase', it originally
meant 'to follow' i.e. 'up the mound in the distance'.