tantamount
adj.adj. equal in value, importance, or effect to something else. You use this when two things are so similar that one can be seen as the same as the other.
adj. equivalent in value, importance, or effect to something else. Often used in the phrase 'tantamount to', which functions as a linking verb.
Refusing to pay the bill is tantamount to a formal complaint.
The government's refusal to negotiate was tantamount to a declaration of war on the trade union.
While the official report was brief, the implications of the findings were tantamount to a complete overhaul of the existing legal framework.
First attested in English in 1628. Either inherited from an unattested Middle English borrowing from Anglo-Norman tant amount, from amunter, from tant (“as much”) amonter (“to amount to”) or borrowed in the early 17th century from Italian tanto montare (“to amount to as much”).