Thou fair-haired angel of the evening … [William Blake]
Talking in a sing-song drone … [Entertainment Weekly]
… a starch-filled potluck of goodness. [Two Vegan Boys]
An adjective phrase beginning with an -ly adverb needs no hyphen—for example:
… that I had realized the goal of her poorly conceived plan. [Wayward Irregular]
So the hyphen here is unnecessary:
Such advertisements are categorized by sparsely-dressed women … [Daily Campus]
2. Hyphens help distinguish between homographs with vastly different meanings—for example, co-op and coop, re-create and recreate, mid-section and midsection. In normal circumstances, the prefixes co-, re-, and mid- are attached to words without a hyphen, but the hyphen brings clarity in cases such as these.
3. Hyphens are occasionally used in compound nouns, although this practice varies, and specific conventions govern each case. Invented compound nouns are usually good candidates for hyphenation; poets often do this with whimsical coinages—for instance:
And the flags where the butter-bump hides in for ever … [John Clare]
There is a long-term trend away from hyphenation. This movement is generally faster in British than U.S. English, but evident in both varieties, and acknowledged by dictionaries like Oxford. For example, ice-cream is now ice cream, to-day and to-morrow are now today and tomorrow, bumble-bee is now bumblebee, and so on.