ATOM ?
Heat
Rest?
hydroelectric
Coal, wind
wire
"Vac" is not a word in English. It is a four-letter combination that does not form a valid word in the English language.
the answer to your question is the word lamp it is four letters and is a compound so good luck with that information.
pep
A four letter word starting with the letter a is able.
A four letter word for 'in addition to' is also.
That Four-Letter Word was created in 2006.
Lard is a four letter word for grease.