1. 容易的：effort 努力 | effortless 容易的 | effraction 侵入

2. 毫不费力的：444. effect 影响;导致-效果 | 445. effortless 毫不费力的 | 446. elaborate 详尽的

3. 不费力气的：efforescencesaltpeteringwhiskering 泛碱 | effortless 不费力气的 | effortlessly 顺水

4. 不作努力的;不费力的,容易的：effigy 假人,模拟像 | effortless 不作努力的;不费力的,容易的 | effrontery 厚颜无耻

1. 不费力的;轻松的
    Something that is effortless is done easily and well.

    e.g. In a single effortless motion, he scooped Frannie into his arms.
           他一下子就轻松地把弗兰尼拥入怀里。
    e.g. ...effortless and elegant Italian cooking.
           简单精致的意大利烹饪

adj

1. not showing effort or strain

    e.g. a difficult feat performed with casual mastery
           careless grace

    Synonym: casual

2. requiring or apparently requiring no effort

    e.g. the swallows glided in an effortless way through the busy air