yance

As adverbs the difference between only and yance

is that only is without others or anything further; exclusively while yance is (dialect|northern english dialect) once (in both senses: only one time, and formerly).

As an adjective only

is alone in a category.

As a conjunction only

is under the condition that; but.

As a noun only

is (rare) only child.

As adverbs the difference between once and yance

is that once is before while yance is (dialect|northern english dialect) once (in both senses: only one time, and formerly).

As a noun once

is before.