IPA: /pərˈtɪnəntli/
KK: /pɜrˈtɪnəntli/
In a way that is relevant or applicable to the matter at hand.
She answered the question pertinently, addressing all the key points.
Pertinently → It is formed from "pertinens" (from Latin, meaning relating to or belonging to) and the suffix "-ly" (meaning in a manner of). The word "pertinently" means in a manner that relates to the matter at hand.
Think of something that is 'related' ('pertinens') to the topic being discussed, and remember that 'pertinently' means addressing the matter directly.