adjective

free of deceit; truthful and sincere.

I haven’t been totally honest with you

truthful,sincere,candid,frank,direct,open,forthright,straight,straightforward,genuine,blunt,plain-spoken,plain-speaking,matter-of-fact,outspoken,as straight as a die,straight from the shoulder,upfront,free-spoken,objective,impartial,unbiased,balanced,unprejudiced,disinterested,even-handed,fair,just,equitable

adverb

used to persuade someone of the truth of something.

you’ll like it when you get there, honest