Here are the possible solutions for they're in everything clue
Answer
Clue
Relevancy
else
Clue
"Everything Louder than Everything ___" (Meat Loaf song)
Definition
otherwise
salt
Clue
Part of the "everything" in an everything bagel
sahl
Clue
Early and influential stand-up comedian Mort who said, "Liberals feel unworthy of their possessions. Conservatives feel they deserve everything they've stolen" haha I feel that
asimov
Clue
"Those people who think they know everything are a great annoyance to those of us who do" quipster
atoms
Clue
They're in everything
They make up everything
Definition
ATOM, the smallest particle in an element which can take part in a chemical reaction