This is the 13880th most frequent Russian word.
обманным
"Deceptive" or "fraudulent."
The word "обманным" ('deceitful') describes the manner of acting, as part of the phrase "обманным путем" ('in a deceitful way').
Он действовал обманным путем в этом деле.
He acted in a deceitful manner in this case.
The word "обманных" ('deceitful') is used as an adjective to describe the noun "обещания" ('promises'), implying that the promises were based on deceit.
Её аргументы основывались на обманных обещаниях.
Her arguments were based on deceitful promises.
The word "обманный" ('deceitful') is used as an adjective to qualify the noun "ход" ('move'), indicating that the move involved deceit.