tõsise
Tõsise is the genitive singular form of the Estonian adjective tõsine, which means serious, earnest, or genuine. It appears when the noun it modifies is in the genitive case, most commonly in attributive phrases such as tõsise mehe nägu, meaning the face of a serious man. In contrast, the nominative singular form tõsine is used directly before a nominative noun (for example, tõsine inimene).
Etymology and sense: tõsine derives from the root tõsi, meaning truth, with the -ne suffix that forms
Morphology: Like other Estonian adjectives, tõsine declines by number and case. In the genitive singular it
Usage: Tõsise is mainly used in formal or written Estonian to express possession or relation in noun