Is introverted a positive or a negative word when describing a person's character? Or a neutral word?

It is a positive word.

Interpretation of introverted:

1. (Character, thoughts and feelings, etc.) Deep, not exposed.

2. (Artistic style) subtle, intriguing.

Near synonyms for introverted: astringent?

1. (Smile, light, etc.) To diminish or disappear.

2. To lessen the degree of indulgence (in reference to speech and behavior).

Citation: haoran 《Yan Yang Tian》Chapter 8.6: "Counterattacking Ma Zhi Yue , you can make the backward rich middle peasants to restrain themselves."

Expanded Information

Antonyms for introverted:

I. Rough? [ cū guǎng ]?

Explanation: rough; rude.

Citation: qin mu 《＜长河浪花集＞序》："The subject matter is both varied and diverse, and we must endeavor to have several sets of brushwork; sometimes it should be rough and majestic, and sometimes it can be delicate and timeless."

Two, overflowing? [ piāo yì ]?

Explanation: floating and overflowing.

Citation: Xiao Jun 《August Countryside》VII："The vat of sorghum wine is open. The aroma of the wine overflows to lure people."