Word Study
synallagmatic
CIDE DICTIONARY
synallagmatic, a. [Gr. , from a mutual agreement, contract, fr. to exchange, negotiate with; sy`n with + to change.].
Imposing reciprocal obligations upon the parties; as, a synallagmatic contract. Bouvier. [1913 Webster]
OXFORD DICTIONARY
synallagmatic, adj. (of a treaty or contract) imposing reciprocal obligations.
Etymology
SYN- + Gk allasso exchange
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