Subdolous is a relatively obscure word that means sly or sneaky. There are several synonyms that can be used to convey the same meaning, some of which include devious, cunning, wily, sly, shifty, artful, and crafty. These words carry connotations of someone who is subtle and operates in a covert manner, often with ill intentions. Other synonyms could include duplicitous, treacherous, conniving, or calculating which emphasizes the idea of someone who is not to be trusted. Alternatively, words like precarious or dubious could be used to describe a situation that is dangerous or uncertain, where a subdolous individual may cause harm.