STUMPERS LXXXIX
Credit: Joseph Appel

The six anagrams for the letters STOP are well-known:

STOP, SPOT, TOPS, OPTS, POTS, POST.

Can you think of another four-letter word that also has six anagrams?

Answer:

RAIL or any of its anagrams:

RAIL
RIAL (monetary unit)
ARIL (seed pod)
LAIR
LIAR
LIRA (monetary unit)