9 letters · 15 points in Scrabble
noun weakness characterized by a lack of vitality or energy
noun the quality of being loose (not taut)
noun the quality of being lax and neglectful
originFrom Middle English slacnesse, slakenes, slaknesse; equivalent to slack + -ness. Compare Old English slæcnes.
Etymology from Wiktionary, CC BY-SA 3.0