couple
n. countablen. two people who are in a relationship, like a married pair. It can also mean a small number of things, usually two or three.
n. two individuals who are married or in a romantic relationship; alternatively, a small indefinite number of items, typically two. Often functions as a collective noun.
The young couple walks through the park every morning.
I only have a couple of dollars left in my wallet after buying lunch.
The architect suggested adding a couple of skylights to the upper floor to maximize the entry of natural light during the winter months.
From Middle English couple, from Old French couple, from Latin cōpula. Doublet of copula.
When referring to a small number, it is almost always followed by 'of' before a noun phrase.
I have a couple books.I have a couple of books.In standard English, 'couple' requires the preposition 'of' before the noun it modifies.