US Swimmer Nicknamed Shark, Multiple Gold Medalist

This page is the CodyCross answer for the clue below from Medieval Times, Group 234, Puzzle 3 (Celtic Britons).

Question is: US Swimmer Nicknamed Shark, Multiple Gold Medalist

and the answer is: MARKSPITZ

Word Meaning:

MARK — (heading) Boundary, land within a boundary.

Definitions from Wiktionary.