This is the 469th most frequent Finnish word.
miljardia
"Miljardia" is the partitive singular form of "miljardi," meaning "billion" in English.
Here, 'miljardin' is in the plural genitive case as it modifies the noun 'euroa' acting in a possessive relational capacity.
Yritys suunnittelee kahden miljardin euroa investointeja.
The company plans to make investments of two billion euros.
'Miljardia' marks the partitive plural case of 'miljardi', highlighting the indefinite aspect of the cost proposed.
Hanke voi maksaa jopa kymmenen miljardia euroa.
The project might cost up to ten billion euros.
Here, 'miljardia' (billion) is in the partitive case indicating a non-discrete, ongoing quantity.