Strictly, rigorously, stringently; with strictness of observance. Now only archaic with respect to commands, questions, or obligation.

Sacredly, scrupulously, inviolably; solemnly. Now rare or Obsolete.

With strictness of conduct or rule. Obsolete.

Without prospect or intention of parting; inseparably.

In accordance with rites; with due form.

Faithfully, conscientiously; strictly, scrupulously; fervently.

In a heedful manner; attentively, carefully.

Scrupulously, punctiliously, conscientiously; so as to conform with strict or exacting standards.

Heedfully; with attention.

Dutifully, duteously. Obsolete.

With rigid and exact adherence to a plan, regulation, etc.; with complete and literal observance of a rule or enactment. Also, according to a…

With minute attention to, or insistence on, points of conduct or etiquette; with strict observance of rules or obligation; scrupulously…

In accordance with ritual or custom; in a ritual way.

(un-, prefix1 affix 5.)

Observantly.

Conscientiously, scrupulously; = religiously, adv. 1b. Now rare.