Suffix with heir

ESS

Think of a common ending that turns a male title into its female counterpart, like "prince" to "princess."

The clue "Suffix with heir" is asking for a word ending that can follow "heir" to form a new word. "Heiress" is the word you get when you add "-ess" to "heir," which is a common suffix meaning a female version of a noun. So, the answer is "ESS," the suffix that turns "heir" (a male inheritor) into "heiress" (a female inheritor). It’s a straightforward example of how suffixes modify meaning.