looseness has 8 distinct synonyms spread across 3 of its 6 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its 2 recorded opposites are fixedness, tightness.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
frequent and watery bowel movements; can be a symptom of infection or food poisoning or colitis or a gastrointestinal tumor
freedom from restraint
“the flexibility and looseness of the materials from which mythology is made”
a lack of strict accuracy; laxity of practice
“misunderstandings can often be traced to a looseness of expression”
the quality of movability by virtue of being free from attachment or other restraints
movement or space for movement
“there was too much play in the steering wheel”
dissolute indulgence in sensual pleasure
Synonyms, antonyms and the broader and narrower relations for looseness come from Princeton University’s WordNet. Full sources and licences.