1.
If you describe a violent action as ~, you mean that it is done without thought and will achieve nothing. (mainly BRIT)
...a plot that mixes blackmail, extortion and ~ violence.
= senseless
ADJ: usu ADJ n disapproval
2.
If you describe a person or group as ~, you mean that they are stupid or do not think about what they are doing.
She wasn’t at all the ~ little wife so many people perceived her to be.
ADJ disapproval
~ly
I was annoyed with myself for having so quickly and ~ly lost thirty dollars.
ADV: ADV with v
3.
If you describe an activity as ~, you mean that it is so dull that people do it or take part in it without thinking.
...the ~ repetitiveness of some tasks.
ADJ disapproval
~ly
I spent many hours ~ly banging a tennis ball against the wall.
ADV: ADV with v