Could be spelled firsthand, one word, or first-hand.
Firsthand: obtained by, coming from, or being direct personal observation or experience "a firsthand account of the war"
primary source
coming directly from actually experiencing or seeing something.
It is used as one word.
no it is not an one word it is of two word
Hipbone is one word.
I think the word "ongoing" is only one word, but it has two syllables that are two separate words.
It is one word.
one word
The word "hairbrush" is typically written as one word, not two.
One word, two syllables
It is one word.