An act of driving dangerously close behind another vehicle.(noun)
Present participle of tailgate.(verb)
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Use "tailgating" in a sentence
"M. O'BRIEN: Kind of gives new meaning to the term tailgating, does it?"
"I actually learned this in Malaysia where tailgating is normal and the clerk at the Hertz Rental Car Agency in Penang told me that if I ran over a local in a village, I should run for it to avoid being lynched on the spot."
"Assuming, of course that tailgating is a problem that requires huge dots on the road."