noun, noun which may take the genitive case particle 'no'
free of charge; charge-free
Used to describe something that does not require payment, often in formal or written contexts.
This service can be used free of charge.
無賃の駐車場を探している。
I'm looking for a free parking lot.
fare evasion; riding without paying
Compound of 無 (mu, 'without') and 賃 (chin, 'fare' or 'charge'). The exact historical derivation is uncertain, but the meaning is transparent from the components.