Reciprocal
- Hybrid (biology)
- Hyperbolic spiral
- Multiplicative inverse
- Reciprocal Public License
- Reciprocal altruism
- Reciprocal averaging
- Reciprocal cipher
- Reciprocal construction
- Reciprocal cross
- Reciprocal determinism
- Reciprocal lattice
- Reciprocal length
- Reciprocal license
- Reciprocal link
- Reciprocal obligation
- Reciprocal polynomial
- Reciprocal rule
- Reciprocating engine
- Reciprocating oscillation
- Reciprocation (disambiguation)
- Reciprocity (disambiguation)
- Sherrington's law of reciprocal innervation