Yes, lunchbox is a common noun, a word for any lunchbox of any kind.
A proper noun is the name of a specific person, place, thing, or a title; for example:
Both "lunch box" and "lunchbox" are correct spellings, but "lunchbox" is more commonly used as a single word.
Microphone is a common noun.
Yes. A compound word combines existing words and has a single meaning that may be more specific than the constituent words. (note that not all compound words are conjoined - there may be a space or hyphen)
"Whales" is a common noun.
The common noun for the proper noun "Linda" is "woman" or "person."
Lunchbox is a common noun. Proper nouns are the unique names of people, places, or things. Common nouns are the words for general things. If a common noun is part of a name, it becomes a proper noun. Pronouns always replace proper and common nouns.
lunchbox
Both "lunch box" and "lunchbox" are correct spellings, but "lunchbox" is more commonly used as a single word.
Common noun
Deacon Lunchbox is 6' 2".
common
Pea is a common noun, and peas is the plural...still a common noun.
A common noun.
Most definitely a common noun.
Camel is a common noun.
Th word tail is a common noun because the first letter of a proper noun is capitalized.
common