Word Search - Half -hearted action
Solution 1:
The adjective dilatory carries, according to Webster's, a negative emphasis:
dilatory:
[a] inclined to defer or put off what ought to be done at once; given to procrastination; delaying; procrastinating; loitering
- a dilatory servant
[b] marked by procrastination or delay; tardy; slow; sluggish ... said of actions or measures
[re-formatted and with minor correction]
Solution 2:
Since you've mentioned that you'd prefer a verb, slack seems to fit the bill nicely.
To be careless or remiss in doing.
slack one's duty.
[American Heritage Dictionary]