Word that add to extra meaning adjectives are?

You're asking about words that modify adjectives to add extra meaning. These are called adverbs.

Here are some examples:

* Very cold (intensifies the adjective "cold")

* Extremely tired (intensifies the adjective "tired")

* Slightly warm (diminishes the adjective "warm")

* Incredibly beautiful (intensifies the adjective "beautiful")

* Perfectly round (specifies the quality of "roundness")

* Rather boring (expresses a mild opinion about the adjective "boring")

Adverbs can describe:

* Degree: How much? (very, extremely, slightly)

* Manner: How? (quickly, slowly, carefully)

* Time: When? (now, later, yesterday)

* Place: Where? (here, there, everywhere)

Let me know if you'd like more examples or have any other questions about adverbs!