Berean Study Bible
So Herodias held a grudge against John and wanted to kill him. But she had been unable,

King James Bible
Therefore Herodias had a quarrel against him, and would have killed him; but she could not:

American Standard Version
And Herodias set herself against him, and desired to kill him; and she could not;

Darby Bible Translation
But Herodias kept it [in her mind] against him, and wished to kill him, and could not:

Douay-Rheims Bible
Now Herodias laid snares for him: and was desirous to put him to death, and could not.

English Revised Version
And Herodias set herself against him, and desired to kill him; and she could not;

Young's Literal Translation
and Herodias was having a quarrel with him, and was willing to kill him, and was not able,