"Lightweight" is one word.
Yes.
She was always a lightweight drinker.The lightweight boxer won the match.The new car was lightweight.
'Lightweight' is an adjective. If you are saying that your mouse is not heavy, you'd say "My mouse is lightweight."
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
The anagram is lithium, a lightweight element.