1. (adjective) able to be refuted

• confutable
• confutative
• refutable

1. (adjective) subject to question

• alleged
• so-called
• supposed
• apocryphal
• debatable
• problematic
• problematical
• doubtful
• dubious
• dubitable
• in question
• equivocal
• fishy
• funny
• shady
• suspect
• suspicious
• impugnable
• self-styled
• soi-disant

2. (adjective) able to be refuted

• deniable

1. (adjective) subject to question

• contestable

1. (adjective) able to be refuted

• confute
• disprove

1. (adjective) subject to question

• unquestionable