1. Not returned in kind
   - unanswered, unrequited

See also: nonreciprocal

• strait and narrow
• Strait of Calais
• Strait of Dover
• Strait of Georgia
• Strait of Gibraltar
• Strait of Hormuz
• Strait of Magellan
• Strait of Messina
• Strait of Ormuz
• straiten
• straitjacket
• straitlaced
• straits
• Straits of Dover
• Straits of Gibraltar
• strake
• stramash
• stramonium
• strand
• strand wolf
• stranded
• strange
• strange attractor
• strange particle
• strange quark