圧縮
あっしゅく · asshuku · JLPT N2 · noun
compaction
🗜️ 圧縮 = pressure (圧) + shrink (縮): press something until it shrinks
圧 (atsu) means pressure, as in 圧力 (pressure). 縮 (shuku) means to shrink, as in 縮む (chijimu). Put pressure on something until it gets smaller and you have compression. Zip files are 圧縮ファイル.