Not trusted. The term trustless often refers to Bitcoin, Ethereum and other blockchain-based networks because the thousands of third parties that validate and mine the transactions are essentially unknown to each other and therefore cannot be trusted. In contrast, a "trusted" entity is a bank or credit card company because they are well known and monitored by government agencies.
Doesn't It Really Mean Trusted?
The trustless term applied to blockchains is actually somewhat contradictory because the whole point of the blockchain architecture is to ensure that no alteration has taken place to existing transactions. The blockchain protocol that manages the operation is indeed trusted to maintain this integrity. See blockchain
and crypto glossary