Definition of "elinvar" []

• Elinvar is a trademark for a kind of steel used for watch springs because its elasticity is constant over a wide range of temperatures (noun)

WordNet. Princeton University. 2010.

• "Guillaume's total compensating balance for high-grade watches and chronometers, which eliminates the secondary error, was perfected by an elinvar hair spring."
• "a very low coefficient of expansion; elinvar, for which the thermoelastic coefficient is practically zero, i.e. Young's modulus constant, over a considerable temperature range; together with other useful alloys."