Unscramble Refidths

What is the meaning of word refidths unscrambled?

What 8 letter words can be made from letters R E F I D T H S:

1. redshift - Definition of redshift

Make more words by adding or removing letters

How many 7 letter words can you make from letters R E F I D T H S?

1. dithers - Definition of dithers

2. redfish - Definition of redfish

3. shifted - Definition of shifted

4. shifter - Definition of shifter

Which 7 letter words can be made by removing one letter and unscrambling the remaining letters?
1) Removing the letter R and unscrambling efidths
2) Removing the letter E and unscrambling rfidths
3) Removing the letter F and unscrambling reidths
4) Removing the letter I and unscrambling refdths
5) Removing the letter D and unscrambling refiths
6) Removing the letter T and unscrambling refidhs
7) Removing the letter H and unscrambling refidts
8) Removing the letter S and unscrambling refidth

More anagrams containing the letters R E F I D T H S
refidtsh refihdst derstihf rdhtefis