遅らす
おくらす · okurasu · JLPT N1 · verb-godan
to delay
⏰ 遅い (osoi, late/slow) + causative らす = make something late = to delay
Stem 遅 (late, slow) plus the causative ending らす gives 'cause to be late', which is the same as delaying something. Compare 遅れる (okureru), to be late.