terveydenja
Terveydenja is not a standard Finnish word or term. It appears to be a concatenation of the genitive form terveyden (of health) and the coordinating conjunction ja (and). In Finnish, conjunctions are written as separate words, so the normal form between two nouns or noun phrases is terveyden ja, not terveydenja.
Terveyden is the genitive form of terveys, meaning health. It is used in compounds and phrases to
In practice, terveyden ja hyvinvoinnin laitos, abbreviated THL, is a prominent example in Finland. This institute,
If used in a non-Finnish or fictional context, terveydenja could be treated as a coined term or