adj. phr. Trustworthy; sure to keep your promise. The coach said he would give the players a day off if they won, and he was as good as his word. We knew she was always good as her word, so we trusted her.
AS GOOD AS ONE'S PROMISE
Meaning of AS GOOD AS ONE'S PROMISE in English
American idioms English vocabulary. Английский словарь американских идиом. 2012