This is the 373rd most frequent Swedish word.
heller
"Neither" or "either" (used in negative contexts).
Here, 'heller' is used to indicate an agreement in negativity, expressing 'neither' or 'either' in a not-so context.
Jag tycker inte om kaffe, och jag dricker inte te heller.
I don't like coffee, and I don't drink tea either.
In this sentence, 'heller' continues the negative statement regarding the action of not going.
Han ville inte gå till stranden, och famlijen följde inte med heller.
He didn't want to go to the beach, and the family didn't come either.
Here, 'heller' similarly reinforces the negativity expressed in the preceding clause.