heavy is raskun (of great weight)

raskun = heavy (adjective) (some things Google found for "raskun": a rare term; a very rare last name; gaming character names; user names; similar Rasku is an unusual last name that can be Finnish; similar raske means heavy, difficult in Estonian; name of a place in Iran)

Word derivation for "heavy" (of great weight) (adjective) :
Basque = astun, Finnish = raskas
Miresua = raskun

Another word for heavy in Finnish is painava.

This meaning of the word heavy appears in Through the Looking-Glass a handful of times.

"...And what IS this on my head?" she exclaimed in a tone of dismay, as she put her hands up to something very heavy, and fitted tight all round her head.