Same Last Name of Two Unrelated U.s. Presidents

This page is the CodyCross answer for the clue below from Prehistory, Group 1254, Puzzle 4 (Gigantopithecus).

Question is: Same Last Name of Two Unrelated U.s. Presidents

and the answer is: JOHNSON

Word Meaning:

JOHNSON — (slang) Penis.

Definitions from Wiktionary.