What does equational mean?
Equational is an adjective meaning relating to, based on, or expressed by means of equations. It appears most often in mathematics and its applied branches, where phrases such as 'equational reasoning' or 'an equational proof' signal that an argument proceeds by manipulating equalities — substituting one expression for another known to be equivalent — rather than by other methods such as induction. The word also has a distinct life in logic and linguistics: an equational sentence or construction is one that asserts that two things are identical, as in 'the morning star is the evening star'. Because it derives from 'equation', which itself traces back through Latin 'aequatio' to 'aequare' (to make equal), the word carries the core notion of equality at every level of its use. It is formal and technical in register, rarely heard outside academic contexts, but indispensable for precise discussion in algebra, theoretical computer science, and semantic theory.
Relating to, based on, or expressed in the form of equations.
"The system admits a complete equational axiomatisation."
Most frequently found in technical writing in mathematics and theoretical computer science.
Expressing or asserting the identity or equivalence of two terms, as in certain logical or linguistic constructions.
"Copular clauses of the form 'A is B' are often analysed as equational sentences."
In computer science, 'equational reasoning' is the idea that you can verify a program simply by treating its code like algebra — substituting equals for equals until the answer falls out.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of equational
Equational derives from 'equation', formed from Latin 'aequatio', a noun of action from 'aequare', meaning 'to make equal', which in turn comes from 'aequus' ('equal, even'). The suffix '-al' was added in English to form an adjective, following the regular pattern seen in words like 'functional' and 'propositional'. Its closest relatives are therefore other English derivatives of the same Latin root, including 'equation', 'equal', 'equate', and 'equator'.
Related word forms
How equational is actually used
A technical term used chiefly in mathematics, logic, computer science, and linguistics; rare in everyday conversation. In formal writing it typically appears attributively before a noun (e.g., 'equational reasoning', 'equational definition').
Easily confused with equational
'Equational' relates to mathematical equations or statements of identity, whereas 'equitable' means fair and impartial.