What is a Lefthide Word™?

Question

_{This is based on the What is a Word/Phrase™ series of Phrase™ and Word™ puzzles, started by JLee.}

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If a word satisfies a certain property, it is called an Lefthide Word™. Use the example word lists below to find the rule. Each word can be tested for whether it is an Lefthide Word™ without depending on other words in these lists.

Note that font and capitalization do not matter.

$$ % set Title text. (spaces around the text ARE important; do not remove.) % increase Pad value only if your entries are longer than the title bar. % \def\Pad{\P{0.0}} \def\Title{\textbf{ Lefthide }} % \def\S#1#2{\Space{#1}{20px}{#2px}}\def\P#1{\V{#1em}}\ \def\V#1{\S{#1}{9}} \def\T{\Title\textbf{Words}^{\;\!™}\Pad}\def\NT{\Pad\textbf{Not}\T\ }\displaystyle \smash{\lower{29px}\bbox[yellow]{\phantom{\rlap{rubio.2018.03.05}\S{6px}{0} \begin{array}{cc}\Pad\T&\NT\\\end{array}}}}\atop\def\V#1{\S{#1}{5}} \begin{array}{|c|c|}\hline\Pad\T&\NT\\\hline % \text{WINDOW}&\text{DOOR}\\ \hline \text{TRUE}&\text{TRUTH}\\ \hline \text{NOTHING}&\text{SOMETHING}\\ \hline \text{FIRE}&\text{FIERCE}\\ \hline \text{WAIT}&\text{WAITING}\\ \hline \text{HERO}&\text{VILLAIN}\\ \hline \text{MAMA}&\text{MOM}\\ \hline \text{ASTRONOMY}&\text{STAR}\\ \hline \text{DAMAGE}&\text{DAMAGED}\\ \hline \text{ENTER}&\text{LEAVE}\\ \hline \text{SWEET}&\text{CANDY}\\ \hline \text{GOD}&\text{ANGEL}\\ \hline \end{array}$$

CSV version:

WINDOW,DOOR
TRUE,TRUTH
NOTHING,SOMETHING
FIRE,FIERCE
WAIT,WAITING
HERO,VILLAIN
MAMA,MOM
ASTRONOMY,STAR
DAMAGE,DAMAGED
ENTER,LEAVE
SWEET,CANDY
GOD,ANGEL

There are a lot more Lefthide words, these are just a few.

Answer 1

Given the strange story of Lord Lefthide and Gustavo Gabriel's contribution to its solution, it seems likely (and the ones I've checked are consistent with this) that a Lefthide Word is

one that occurs in the title of a Metallica song.