I sometimes amuse myself with pastimes like this. Can you think of any other 4x4 words? Keep your eyes open, and post them (the words, not your eyes, you fool).
ares/arse/ears/eras/sear/sera (looted from Gaby 'n Fish)
eels/else/lees/seel (pillaged from Gaby 'n Fish) * # †
hits/sith/$&@%/this (נגנב מיש לנו הרבה בקוונים
lair/lari/liar/lira/rail (lifted from DoughBoy)
part/prat/rapt/tarp/trap (thieved from DoughBoy)
* Extra marks for repeated letter.
# Besides, who knew that "seel" was a word (The Official Scrabble Players Dictionary, Second Edition: "to stitch closed the eyes of, as a falcon during training")?
† Jesus is Lord!