Wiktionary
lightning-quick
a. (context idiomatic English) Incredibly fast
Usage examples of "lightning-quick".
Upon battling the lightning-quick Baenre, Drizzt had come to believe those rumors, and after wearing the bracers in sparring for the last few weeks, he had confirmed their abilities.
The beach-comber was aware of a lightning-quick tensing of the slumped muscles.
With a lightning-quick strike of his machete, Claudio cut off the head of a deadly pit viper.