Cognomen Coustant (Кустан 
, Coustant 
) , in the world, is a very rare last name. The family name Coustant is habitual in France, where it is a very rare surname, and the United States, where it is an extremely rare surname. Also, Coustant is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Кустан | Kazakhstan |
| Coustant | France, United States |
| pierre coustant French Benedictine scholar (1654-1721), FR (b. 1654) |
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| charles coustant de belle-assise French jurist and lawyer (1676-1752), FR (b. 1676) |
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| raymond coustant d'yanville French politician (1862-1941), FR (b. 1862) |
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