Yes. It originates from belief which is the noun referring to a person believing in something, as well as the negating prefix dis.
Upwards is a compound word.
Upstairs is a compound word, so it is one word.
A non compound word is , a word with one word not two . For a example a compound word is snowflake. An non compound is hot cheetos.
No, the word ability is not a compound word.
No. The word fast is not a compound word.
The root word is belief.
I look at the kids in disbelief for their terrible behavior.
Disbelief. Disbelief: Adj. Lit., does not believe.
disbelief, doubt, unexpected, uncertain, ambiguous
The man was in total disbelief when he found out he made the show.
She looked in disbelief at the driver who was yelling obscenities.
Incredulity.
Rejection, disbelief
denial
Anarchy
Dis - be - lief . 3.
Doubt disbelief skeptical skeptic