epsiloniser

Insider mathematical slang, not standard dictionary French, meaning to rewrite a statement using formal epsilon-delta language (the rigorous definitions behind limits, continuity, or compactness) — and, by extension among mathematicians, to make something needlessly rigorous and hard to read.

• Le professeur a epsilonisé la démonstration pour la rendre rigoureuse. — The professor rewrote the proof in epsilon-delta form to make it rigorous.
• Inutile d'epsiloniser cet énoncé, l'idée est déjà claire. — No need to formalize this statement with epsilons, the idea is already clear.
• Les étudiants détestent epsiloniser leurs preuves de topologie. — The students hate having to formalize their topology proofs with epsilons.

This is jargon confined to math students and academics, not standard vocabulary — a learner will essentially never encounter it outside a French-language math course or paper.