This is the 110th most frequent Lithuanian word.
gyvenimo
"Gyvenimo" means "of life" in English.
Here, "gyvenimo" is in the genitive case indicating possession or relation to "prasmė" (meaning).
Gyvenimo prasmė yra tai, ką mes patys sukuriame.
The meaning of life is what we create ourselves.
In this sentence, "gyvenimo" describes "būdą" (lifestyle) showing a descriptive relationship.
Aš perskaičiau įdomią knygą apie gyvenimo būdą.
I read an interesting book about lifestyle.
"Gyvenimo" in this example modifies "patirtis" (experience), associating it specifically with "life".