Noun

• S: (n) twin (either of two offspring born at the same time from the same pregnancy)
• S: (n) Gemini, Twin ((astrology) a person who is born while the sun is in Gemini)
• S: (n) Twin, Twin Falls (a waterfall in the Snake River in southern Idaho)
• S: (n) counterpart, similitude, twin (a duplicate copy)

Verb

• S: (v) twin, duplicate, parallel (duplicate or match) "The polished surface twinned his face and chest in reverse"
• S: (v) match, mate, couple, pair, twin (bring two objects, ideas, or people together) "This fact is coupled to the other one"; "Matchmaker, can you match my daughter with a nice young man?"; "The student was paired with a partner for collaboration on the project"
• S: (v) twin (grow as twins) "twin crystals"
• S: (v) twin (give birth to twins)

Adjective

• S: (adj) duplicate, matching, twin, twinned (being two identical)
• similar to
• antonym