That is a matter of opinion; not certain; debatable, conjectural. Also occasionally as n. Now chiefly archaic.

Of the nature of, or expressing, an opinion; founded on opinion; conjectural, uncertain.

= opinional, adj.

Of the nature of or based on opinion; conjectural.

Based on opinion; held as opinion; conjectural, uncertain. Obsolete.

Conjectural; of the nature of an opinion rather than fact; = opinative, adj. 1, opinionative, adj. 2. Obsolete.

Of or relating to opinion.

Of or pertaining to opinion; depending on or exercising opinion. Also as n. An object of opinion.

Of the nature of an opinion; expressing opinion. rare.