1) A sentential adverb -- it's a single word or short phrase, usually interrupting normal syntax, used to lend emphasis to the words immediately proximate to the adverb. Compare:
- But the lake was not drained before April.
- But the lake was not, in fact, drained before April.
- I came, I saw, I conquered.
- She likes pickles, olives, raisins, dates, pretzels.
- "The water, like a witch's oils, / Burnt green, and blue, and white." --from Samuel Taylor Coleridge
- "Hey! Assbutt!" -- The angel Castiel getting archangel Michael's attention in the Season 5 Supernatural episode right before he sets him on fire with holy oil. Calling Archangel Michael an "assbutt" is really funny understatement in the context of the show and had me and others laughing.
- Heat waves are common in the summer.
- Heat waves are not rare in the summer.
- (something) was dark black. Or, alternately, "He stared at me with his dark gaze while I lusted over his perfect features."
You are wonderful :)