The difference between Nonpareil and Only

When used as nouns, nonpareil means a person or thing that has no equal, whereas only means an only child.

When used as adjectives, nonpareil means unequalled, unrivalled, whereas only means alone in a category.

Only is also conjunction with the meaning: under the condition that.

Only is also adverb with the meaning: without others or anything further.

check bellow for the other definitions of Nonpareil and Only

Nonpareil as a noun:

A person or thing that has no equal; a paragon.
Nonpareil as a noun (cooking, US):

A small pellet of colored sugar used as decoration on baked goods and candy.

Examples:

"synonyms: [[hundreds and thousands]] q UK Australian plural only [[sprinkles]] q US"
Nonpareil as a noun:

A small, flat chocolate drop covered with white pellets of sugar, similar to a comfit.
Nonpareil as a noun:

A smaller grade of caper.
Nonpareil as a noun (uncountable, dated, printing):

The size of type between agate and minion, standardized as 6-point.

Examples:

"synonyms: [[nonpareille]] q Continental contexts"

Only as an adjective:

Alone in a category.

Examples:

"He is the only doctor for miles."

"The only people in the stadium were the fans: no players, coaches, or officials."

"That was the only time I went to Turkey."
Only as an adjective:

Singularly superior; the best.

Examples:

"He is the only trombonist to recruit."
Only as an adjective:

Without sibling; without a sibling of the same gender.

Examples:

"He is their only son, in fact, an only child."
Only as an adjective (obsolete):

Mere.

Only as an adverb:

Without others or anything further; exclusively.

Examples:

"My heart is hers, and hers only. The cat sat only on the mat. It kept off the sofa."
Only as an adverb:

No more than; just.

Examples:

"The cat only sat on the mat. It didn't scratch it. If there were only one more ticket!"
Only as an adverb:

As recently as.

Examples:

"He left only moments ago."
Only as an adverb (obsolete):

Above all others; particularly.