Ask at the forum if you have an Ancient or Modern Greek query!

τούτῳ

Ἐς δὲ τὰ ἔσχατα νουσήματα αἱ ἔσχαται θεραπεῖαι ἐς ἀκριβείην, κράτισται -> For extreme diseases, extreme methods of cure, as to restriction, are most suitable.
Corpus Hippocraticum, Aphorisms 1.6.2

French (Bailly abrégé)

dat. sg. masc. et neutre de οὗτος.

English (Strong)

dative case singular masculine or neuter of οὗτος; to (in, with or by) this (person or thing): here(-by, -in), him, one, the same, there(-in), this.

Russian (Dvoretsky)

τούτῳ: dat. к οὗτος и τοῦτο.