Byron P. answered 09/20/20
Bar Exam & Law School /1st in Law School/Rhodes Nominee/Professor
In Jurisprudence (the Philosophy of Law), the term "Constructive" refers to a "legal fiction" or "legal construct" designed to fashion a basis for a claim or legal principle from which a remedy or right can be built, seemingly out of whole cloth.
A constructive trust is imposed in equity (vs. the law side of the court) when there are facts suggesting that a party holds funds or other "res" (Latin-“thing”) which, if kept by defendant, would result in a defendant's unjust enrichment.
This "looks like a trust and walks like a trust" way of viewing the situation permits the court to treat a defendant as a fiduciary to the plaintiff (surely a responsibility that the defendant [who perhaps acquired the res by fraud] would- except in the face of a court order with jail in the event of noncompliance- decline) and will require that the res be transferred to the court, the court clerk's registry, or a court appointed Custodian or Sequestrator (or perhaps a court might freeze a defendant's bank account where funds in question are maintained).