Peter Murphy "His Circle and ___ Meet"

• Possessive contained in "theirs"
• That woman's
• Belonging to that woman
• Word on either matching towel, for some couples
• Half a matched set, perhaps
• Towel term
• Towel tag
• For the lady
• Bierce defines it "His"

Wiktionary Word definitions in Wiktionary
pron. That which belongs to her; the possessive case of she, used without a following noun.