transcription, транскрипция: [ tæntəmaʊnt ]
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. ( FORMAL )
What Bracey is saying is tantamount to heresy...
ADJ : v-link ADJ to n / -ing [ emphasis ]