with ease
Synonym discussion
Sense: idiom/1
All four expressions describe doing something with little difficulty, but they differ in tone and position. 'Easily' is the most neutral and flexible — it can sit before or after the verb ('She easily passed the exam' / 'She passed the exam easily'). 'Effortlessly' is more emphatic, suggesting the task costs the person nothing ('The pianist played the difficult piece effortlessly'). 'With ease' is slightly more formal than 'easily' and always follows the verb ('He solved the problem with ease'). 'Without trouble' is the most casual and everyday ('The children set up the tent without any trouble'). 'Smoothly' focuses on the process being uninterrupted rather than effort-free ('The meeting ran smoothly').
Etymology
The phrase 'with ease' combines the preposition 'with' (from Old English 'wiþ') and 'ease', which entered English through Old French 'aise' (comfort, convenience) and ultimately from Latin 'adjacens' (lying near, neighbouring). The sense of 'freedom from difficulty' developed in Middle English.