"Flee" is unique in its spelling and pronunciation. However, there are words that are close in sound or spelling but have different meanings:
Similar sounding words:
* flay: to strip the skin off (as in "flay a carcass")
* flea: a small, wingless insect that feeds on the blood of mammals and birds
Similar spelling words:
* flee: to run away from danger
* fleet: a group of ships or vehicles
While these words are not true homonyms, they can be confusing if you are not familiar with the different meanings.