Germane
Etymology
From Latin "germānus," "having the same parents, genuine," linked to "germen" ("sprout, offshoot"). Middle English used germane to mean literally akin, as in "brothers germane." Shakespeare stretched the family metaphor — "closely related" — into "closely relevant," and that extended sense became the standard one.
adjective · /jer-MAYN/
Genuinely relevant to the matter at hand.
What it names
Sharper than "related" — the germane fact bears directly on the point under discussion, and its relevance is close and pertinent rather than merely nearby.
Example
That’s an interesting story, but is it germane to the budget we’re supposed to be settling?
Related idea
Contrast tangential: the tangential remark only grazes the subject, while a germane one is bound tightly to it.