aˌbove ˈboard / $ .ˈ../ adjective [not before noun]
honest and legal:
His plans for opening a coffee shop are completely above board.

[TahlilGaran] Dictionary of Contemporary English ▲

honest always saying what is true, and not cheating, stealing etc:
I liked them because they were good honest people.
You can trust Noah – he’s totally honest.
reputable known to be honest and good in your business or work – used about people, companies, or organizations:
It’s best to buy from a reputable company.
They were highly reputable sports physicians.
above board [not before noun] honest and legal – used about the way something is done, organized etc:
The deal was entirely above board.
Was the voting in the elections above board?
upright written always behaving in an honest way:
an upright citizen
George was an upright man from a military family.
straight informal honest and saying what you really think:
I can’t help you if you’re not straight with me.
I need a straight answer.
open willing to talk about what you think, feel etc in an honest way, rather than trying to hide it:
People have become more open about their feelings.
She’s very easy to talk to because she’s so open.
frank speaking honestly and directly about something, especially something that people find difficult to discuss:
In his book, he’s brutally frank about his experience with his illness.
a frank discussion about sex
direct saying exactly what you think in an honest clear way, even when this might annoy or upset people:
Not everyone liked his direct manner.
She can be very direct.
blunt speaking in a completely honest way, even if it upsets people, when it would be better to be more careful or polite:
Sorry if I was a bit blunt with you.
His hard tone and blunt words were hurtful.
She didn’t reply and I knew I had been too blunt.
upfront [not before noun] informal talking and behaving in an honest way, even when it is difficult to do this, in a way that people respect:
It’s best to be upfront about your financial problems.
You have to be upfront with kids.
outspoken expressing your opinions publicly in a very direct way, which may offend or annoy some people:
an outspoken critic of the government
He was known for his outspoken views on various controversies.
forthright formal saying exactly what what you think, without being afraid of what other people will think:
The opposition have not come up with a clear forthright statement of their policies.
At times, Helena was a little too forthright.
candid formal honest about the facts, or about your opinions and feelings, even if other people disapprove of them:
He’d always been completely candid about his past.
It was an unusually candid admission for a politician.

[TahlilGaran] English Thesaurus ▲

above board
honest, not secret (originally players showed their honesty by keeping their hands above the board when playing a game)
The real estate agent was always above board when dealing with people who were trying to buy a house.

[TahlilGaran] English Idioms Dictionary ▲