Reduction, Cutback
noun, verbal noun
Whittle down and decrease something. This is a reduction or cutback, since you're whittling down and decreasing it.
さくげん
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
コストの削減に苦戦しています。
I’ll have a hard time reducing the cost.