密集
みっしゅう · misshuu · JLPT N1 · noun
crowd
密 — 宀 roof + 必 (phonetic) + 山 mountain
Originally referring to a hidden, sheltered place in the mountains, 密 combines 宀 (roof/cover) over 必 (phonetic) with 山 (mountain) at the base. The meaning extended from 'secluded mountain hideaway' to 'dense, close, secret'. Today it commonly means dense, intimate, or secret.
集 — bird 隹 on top of tree 木
集 is an ideograph showing a bird (隹) perched on a tree (木). The original form depicted three birds gathering on a tree, later simplified to one. From 'birds flocking together' it extended to mean 'gather, collect, assemble,' and by extension 'collection' or 'volume' of writings.