“Designated” time

Question

Is designated acting as a noun or adjective? I have looked up all the dictionaries, but to no avail. Based on my understanding, designate is commonly used to appoint someone or give something a specific status, but I kept seeing people using designated time. Is this informal?

Dictionary.com

1. to mark or point out; indicate; show; specify.

2. to denote; indicate; signify.

3. to name; entitle; style.

4. to nominate or select for a duty, office, purpose, etc.; appoint; assign.

adjective named or selected for an office, position, etc., but not yet insta

Cambridge Dictionary

1. to choose someone officially to do a particular job:

2. to say officially that a place or thing has a particular character or purpose:

Macmillan 1 to formally choose someone or something for a particular purpose

2 FORMAL to give someone or something a particular name, title, or description

3 to represent something in a particular way, for example with a sign or symbol

Answer 1

I assume you mean a sentence like this one:

Please arrive no later than the designated time.

In a sentence like that, the word designated functions as an adjective, modifying time.

Many verbs can be made into adjectives by adding an -ed or an -ing. Here are a couple examples, from the verbs dance and fade:

The dancing clown entertained the audience.

His faded jeans looked worn and comfortable.

Not every dictionary will list every variant of a word, or every give variant its own entry, but I've noticed that Wiktionary (which gets listed at Wordnik), does a pretty good job with this. For example, going to the Wordnik pages, we can see:

dancing

• adj. Describing something or someone that is currently in the act of dancing. (See dance.)
• n. The activity of dancing (see the verb dance).
• v. Present participle of dance.

designated

• v. Simple past tense and past participle of designate.
• adj. Having a specified designation

faded

• v. Simple past tense and past participle of fade.
• adj. That has lost freshness, color, or brightness; grown dim.

It's not informal; it's just English flaunting its flexibility muscles.