まるで "marude" has two basic meanings:
1. "just like"
When used in this manner, まるで is often followed by よう or みたい.
Sumisu san wa Nihongo ga jouzu de, marude Nihonjin no you da.
Smith is good in Japanese that he speaks like a Japanese.
Ano roujin wa marude akanbou mitai da.
That old man is just like a baby.
In negative sentences, まるで has the same function as まったく "mattaku" and ぜんぜん "zenzen". However, まるで implies the speaker's negative judgement.
Miura, Akira. Essential Japanese Vocabulary, Tuttle.