pinpoint
noun
a very brief moment
“they were strangers sharing a pinpoint of time together”
a very small spot
“the plane was just a speck in the sky”
Synonymsspeckthe sharp point of a pin
verb
locate exactly
“can you pinpoint the position of the enemy?”
“The chemists could not nail the identity of the chromosome”
Synonymsnail
Source: WordNet 3.1, Princeton University