Unscramble Itfsets

What is the meaning of word itfsets unscrambled?

What 7 letter words can be made from letters I T F S E T S:

Make more words by adding or removing letters

How many 6 letter words can you make from letters I T F S E T S?

1. feists - Definition of feists

2. testis - Definition of testis

Which 6 letter words can be made by removing one letter and unscrambling the remaining letters?
1) Removing the letter I and unscrambling tfsets
2) Removing the letter T and unscrambling ifsets
3) Removing the letter F and unscrambling itsets
4) Removing the letter S and unscrambling itfets
5) Removing the letter E and unscrambling itfsts
6) Removing the letter T and unscrambling itfses
7) Removing the letter S and unscrambling itfset

More anagrams containing the letters I T F S E T S
itfsset itfsste tfteiss tfseist