まるで

まるで〈物もの〉のようだas if it were ~; just like ~
彼かれはまるで子こ供どものようだ。
He is just like a child.
まるで〈動どう詞し〉ないnot at all; not in the slightest (with a negative verb)
彼かれの説せつ明めいはまるで分わからない。
I don't understand his explanation at all.
〈物もの〉がまるで違ちがうis completely different from ~
二ふたつの案あんはまるで違ちがう。
The two proposals are completely different.
まるで〈物もの〉みたいだlooks exactly like ~ (casual)
この花はなはまるで本ほん物ものみたいだ。
This flower looks just like a real one.

Grammar

まるで～ようだ・かのようだjust like; as ifN3

Kanji

丸round, full (month), perfection

Related words

全まったくN3
まったく is a broad intensifier for 'completely' or 'not at all', while まるで leans toward vivid comparisons (as if/just like) as well as total negation.
全ぜん然ぜんN5sense 2
全然 is used mainly with negatives for 'not at all' (and casually with positives), whereas まるで also covers the 'as if/just like' comparison sense that 全然 lacks.
あたかもN2
まるで is the common, everyday word for 'as if,' while あたかも is more literary and emphatic and typically appears in formal or written Japanese.
さもN1
まるで sets up a simile meaning 'as if/completely', whereas さも stresses that a situation truly seems real rather than comparing it to something else.
ちょうどN4
まるで stresses a vivid, almost exaggerated resemblance before ように/みたいに, while ちょうど conveys a milder, matter-of-fact 'just like' comparison.

Don't confuse with

まるっきりN1sense 3
まるっきり sounds and looks similar to まるで and means much the same 'completely/not at all', but it is a more colloquial variant that cannot be used before ようだ/みたいだ comparisons the way まるで can.

Written forms

まるでUsage100%
Standard practical spelling; usually written in kana.
丸まるでUsage<1%
rarely-used kanji form
Attested kanji spelling, but marked as rarely used; use まるで in ordinary writing.

Etymology

The rare kanji spelling 丸で links the word to 丸, associated with wholeness or completeness, plus で. In modern Japanese it functions as an adverb and is normally written in kana.