Have you heard of the word, Umami?
Umami (/uˈmɑːmi/), or savory taste, is one of the five basic tastes (together with sweetness, sourness, bitterness, and saltiness). — Umami (From Wikipedia)
It’s a Japanese loanword, but the taste is universal.
Have you ever found it hard to describe the subtle taste of Dashi stock(Japanese Dashi broth)?
Not sweet, not sour, not bitter, not salty, but tasty!!!