While Thou __ Keep a Good Tongue in Thy Head

This page is the CodyCross answer for the clue below from World of Sounds, Group 1357, Puzzle 4 (Jet Engines).

Question is: While Thou __ Keep a Good Tongue in Thy Head

and the answer is: LIVEST

Word Meaning:

LIVEST — (archaic) second-person singular simple present indicative of live

Definitions from Wiktionary.