I agree with 1dn. as I aman educated man (ha! ha!) I thought that it mighr be a slang term
I have difficult6y with 5dn, unless it's a knitting term,but then not a good clue
Still don't get the gas one: if it's what I think (the only gas in the list that fits) can't see where the 1st letter comes from, either. Or what am I missing? Has the proverbial penny dropped for the others or not?