adverb, adverb taking the 'to' particle
remarkably; rapidly; by leaps and bounds
Describes noticeable, often rapid improvement or progress, typically in skill or ability.
彼は練習を始めてからメキメキ上達した。
He improved remarkably after he started practicing.
新入社員がメキメキと力をつけている。
The new employee is rapidly gaining skills.
adverb, adverb taking the 'to' particle
creaking; cracking sound
Mimetic use for the sound of something straining, creaking, or breaking under pressure. Less common than the progress sense.
古い床板がメキメキと音を立てた。
The old floorboards made a creaking sound.