Mekely is the middle English version of the modern word meekly. The person before me has the definition of meekly correct. Middle English would be used in a work like The Canterbury Tales, by Geoffrey Chaucer, which was published in 1475.

In what terms are refering to the word? If you are refering to meekly and just have it misspelled then it is one who shows no signs of pride or self-assertion. 

 The boy meekly accepts that his friend takes advantage of him because he has the dominant personality.