This is the 4583rd most frequent Chinese word.
毫無
"毫無" means "completely without" or "totally lacking."
The term 毫無 in this sentence stresses the total absence of logic in the explanation.
那份解釋毫無邏輯可言。
That explanation has absolutely no logic.
Here, 毫無 denotes the complete lack of interest of the person in helping others.
他對幫助別人毫無興趣。
He has absolutely no interest in helping others.
In this sentence, 毫無 is used to emphasize that there is no doubt at all about the correctness of the matter.