Modifiers matching synthetic:

• new,
• stretchy,
• thin,
• hydrophobic,
• modern,
• stretchable,
• thermoplastic,
• durable,
• stronger,
• polymeric,
• traditional,
• heavy,
• colour,
• strong,

Simple categories matching stronger:

• web,
• material,
• emotion,
• animal,
• beer,
• entity,
• component,
• alloy,
• adversary,
• metal,
• rock,
• fish,
• fibre,
• synthetic,
• predator,
• opponent,
• light,
• force,
• structure,
• character,
• unit,
• drug,
• passion,
• prey,
• analgesic,
• power,
• substance,
• glue,
• ability,
• wood,
• dragon,