This is the 2108th most frequent Korean word.
연준이
"연준이" is not a standard Korean word; it is likely a proper noun, such as a person's name (e.g., Yeonjun-i).
In this example, '연준이', followed by the subject particle '가', describes who made the cake.
연준이가 만든 케이크가 정말 맛있었어요.
The cake that Yeonjun made was really delicious.
In this sentence, '연준이' is used as the subject's name with the subject particle '는'.
연준이는 오늘 학교에 갔어요.
Yeonjun went to school today.
Here, '연준이' is used with '와', indicating an accompaniment with Yeonjun.