slackness

The character or state of being slack, in any sense.

A tendency of a vessel under sail to fall off or away from the direction of the wind when the helm is amidships: opposed to ardency.

The quality or state of being slack.

The state of being slack; the quality of having slack.

the quality of being loose (not taut)

weakness characterized by a lack of vitality or energy

the quality of being lax and neglectful