形容词

1. （恐惧、指控、报道等）无理由的，无根据的
If you say that a fear, accusation, or story is groundless, you mean that it is not based on evidence and is unlikely to be true or valid.

1. without a basis in reason or fact

e.g. baseless gossip
the allegations proved groundless
idle fears
unfounded suspicions
unwarranted jealousy

Synonym: baselessidleunfoundedunwarrantedwild