ADJ (用于强调非常糟糕、难以接受或不幸)几乎是…,简直是…,无异于… If you say that one thing is tantamount to a second, more serious thing, you are emphasizing how bad, unacceptable, or unfortunate the first thing is by comparing it to the second. (用于强调非常糟糕、难以接受或不幸)几乎是…,简直是…,无异于… [formal, emphasis]
What Bracey is saying is tantamount to heresy. [+ to]
布雷西的言论简直就是异端邪说。
To neglect or forget aspects of the past is tantamount to rewriting history, and anyone who has read Animal Farm knows where that can lead.