Flattened adverbs are provided in this article. The words listed here are commonly found along with the verb flattened in sentences. This reference page helps answer the question what are some adverbs that describe or modify the verb FLATTENED.
completely, generally
laterally, nearly
slightly, strongly
usually
Hope this word list had the flattened adverb you were looking for. In addition to adverbs used with flattened, other example verb adverb pairings can be found on this site.
You can help by adding more adverbs in the comments. Thanks.