IPA: //ˈsʌbˌsiːkwəns//
KK: /sʌbˈsiːkwəns/
A series of elements that appear in the same order as they do in another larger series, but not necessarily consecutively.
In mathematics, a subsequence can be derived from a sequence by removing some elements without changing the order of the remaining elements.
Subsequence → It is formed from "sub-" (meaning under or below) and "sequent" (from Latin "sequentem", meaning following). The word "subsequence" refers to a sequence that follows another sequence, often in a hierarchical or ordered manner.
Think of something that comes 'under' ('sub-') another thing that is 'following' ('sequent'). This helps you remember that a subsequence is a sequence that follows another.