What's the technical term for a mixed metaphor?

"We'll burn that bridge when we come to it." The classical rhetorical term for that kind of collision is catachresis (kuh-TAK-ruh-sis), a trope of meaning that covers strained or misapplied metaphor and historically takes in the mixed-metaphor case. Two other terms circulate for the same family: malaphor, a 1976 coinage for two idioms colliding, and metalepsis, sometimes proposed for a deliberate, multi-step transfer. Scholars don't fully agree on where catachresis ends and ordinary mixed metaphor begins, so the honest answer is "catachresis, with caveats." Which one you actually reach for depends on what got mixed and whether the writer meant it.

Why is catachresis the classical answer?

In the rhetorical tradition, catachresis names a word or metaphor wrenched out of its proper sense. Quintilian treats it in the Institutio Oratoria (8.6) as the abusio, the "misuse" by which a writer reaches for an existing word to cover something the language has no proper name for, or pushes a metaphor past the point where the mapping holds. George Puttenham, glossing it in English in The Arte of English Poesie (1589), called it "the figure of abuse" and gave it the working definition that has stuck: a term applied where it doesn't strictly fit, sometimes by force of necessity, sometimes by error.

That older usage is wide enough to include both kinds of failure the modern reader thinks of. The deliberate strain: Hamlet's "to take arms against a sea of troubles" (Shakespeare, Hamlet, 1601), where the metaphor of armed combat is pushed onto the wrong target and the mismatch is the figure. The accidental clash: a politician's "we will burn that bridge when we come to it," where two live idioms collide and the figure is unintentional. The classical tradition treats both as catachresis.

Strict modern usage sometimes pulls the term tighter. Some handbooks restrict catachresis to the deliberate strain and leave "mixed metaphor" as the lay name for the unintended kind. The line is fuzzy and there isn't full agreement. The strict-and-loose split inside catachresis itself is what most modern handbook treatments leave out.

How does it compare to malaphor and metalepsis?

The three terms cover overlapping ground but each has a use the others don't quite fit. Hold the phenomenon constant (a "mixed" figure) and the distinction is in what got mixed and whether the writer meant it.

Term	One-line definition	When it applies	Register	Example
Catachresis	Misapplied or strained metaphor; a word forced past its proper sense	Two metaphors clash, or a single metaphor is pushed where it doesn't fit (deliberate or accidental)	Classical	"to take arms against a sea of troubles" (Hamlet, 1601)
Malaphor	A blend of two idioms or fixed expressions	Two idioms collide and produce a third, broken one (almost always accidental)	Informal, modern	"we'll burn that bridge when we come to it"; "that train has sailed"
Metalepsis	A figure of transferred reference, typically a chained or multi-step metaphor	A metaphor builds across two or more transfers (A stands for B which stands for C), usually deliberate	Classical	"I've got a lead foot": lead stands for heavy, which stands for fast-driving

Malaphor is a 20th-century coinage. The columnist Lawrence Harrison proposed it in a 1976 Washington Post piece, blending malapropism and metaphor, and it has since settled into editing and copy circles as the precise name for the idiom-collision case. It is informal in the sense that the rhetorical handbooks don't carry it, but it is now the term most editors will recognize for that specific failure.

Metalepsis sits in classical rhetoric as a kind of transferred metaphor (Puttenham called it "the far-fet") and is the term reached for when the figure works by chaining several substitutions in sequence rather than by a single mismatch. The English Stack Exchange answer reaches for it when the mixed metaphor is deliberate and multi-step. Metalepsis itself is narrower than catachresis: it requires the chaining, not just the strain.

The practical test: did two idioms collide? Malaphor. Did the figure work by chaining transfers across multiple steps? Metalepsis. Otherwise, if you need a technical name for a mixed or strained metaphor, catachresis is the term the rhetorical tradition gives you.

Which term should you actually use?

For most working contexts, "mixed metaphor" is still the term other writers will recognize without a gloss. Catachresis is correct, but outside academic or technical-rhetoric writing it reads as classical-rhetoric jargon and slows the sentence down. Use it when you need to name a deliberate strain (a writer pushing a metaphor on purpose), or when the audience is one that uses the term: composition courses, rhetoric scholarship, technical editing on figures.

If two idioms collided, "malaphor" is more precise than "mixed metaphor" and is now common enough in editing circles to use without a gloss. It does work that "mixed metaphor" can't. It tells the reader what specifically went wrong (idioms, not metaphors), which is the diagnosis the writer needs to fix it.

If the figure is deliberately strained or chained across several transfers, reach for catachresis in general writing, or metalepsis in scholarly writing where the multi-step structure is what you're naming. Either way, gloss it on first use.

The default rule: don't reach for the Greek term when "mixed metaphor" already communicates. The technical names earn their place when you need precision the plain phrase can't carry.

How is a mixed metaphor different from a dead metaphor?

A mixed metaphor combines two live metaphors that clash. A dead metaphor is a single metaphor whose figurative sense has worn off through repetition: "leg of the table," "running for office," "the foot of the mountain." The reader no longer sees the comparison; the word has settled into a literal-adjacent use.

The two failures are different. A mixed metaphor breaks because the figurative sense is too active in both halves and they don't combine. A dead metaphor doesn't break at all. It works precisely because its figurative sense is no longer active. Mixing dead metaphors usually doesn't produce a mixed metaphor (no one objects to "we'll head down that road when we come to it"). Mixing live ones does. The basic definition of a mixed metaphor sits underneath all of this, and is the right starting point if the term itself is new. Picking the right technical name is useful, but in most prose "mixed metaphor" is still the word that does the work.