slack

1 : not using due diligence, care, or dispatch : negligent

2a : characterized by slowness, sluggishness, or lack of energy a slack pace

b : moderate in some quality especially : moderately warm a slack oven

c : blowing or flowing at low speed the tide was slack

3a : not tight or taut a slack rope

b : lacking in usual or normal firmness and steadiness : weak slack muscles slack supervision

4 : wanting in activity : dull a slack market

5 : lacking in completeness, finish, or perfection a very slack piece of work

Definition of slack