Noun
(law, dated) The legal money of a country.
Synonym: legal tender
(figuratively) Something that is valued like money within a particular context.
Source: en.wiktionary.orgNothing matters at all. Survival is the coin of the realm. Time is a river with banks. Barry Malzberg
TENACITY, n. A certain quality of the human hand in its relation to the coin of the realm. It attains its highest development in the hand of authority and is considered a serviceable equipment for a career in politics. Ambrose Bierce
There's a nastiness out there that wants to harm me with words. These are my enemies - the ideologues, the populists, the columnists who don't like the fact that I take them on toe-to-toe. What I try to do is tell the truth. It's not the coin of the realm in politics. Ed Koch
During this period, the livre main and the sou main were counting units; only the denier main was a coin of the realm. Source: Internet
Particularly in Kent, because of a shortage of small-denomination coin of the realm, many growers issued their own currency to those doing the labor. Source: Internet
This is the coin of the realm I use in my words – Vision. Source: Internet