From Longman Dictionary of Contemporary Englishslow down phrasal verb1 SLOWto become slower or to make something slower Growth in sales has slowed down.slow somebody/something ↔ down The ice on the road slowed us down.2 BUSY/HAVE A LOT TO DO#to become less active or busy than you usually are It is important to slow down, rest, and eat sensibly. → slow→ See Verb table
Examples from the Corpus
slow down• We could have been here hours ago, but the rain slowed us down.• Everyone's always rushing around trying to get things done - we all need to slow down and take it easy.• Slow down! You're driving too fast!