instant
noun
a very short time (as the time it takes the eye to blink or the heart to beat)
“if I had the chance I'd do it in a flash”
a particular point in time
“the moment he arrived the party began”
adjective
occurring with no delay
“relief was instantaneous”
“instant gratification”
Synonymsinstantaneousin or of the present month
“your letter of the 10th inst”
Synonymsinstdemanding attention
“clamant needs”
“a crying need”
Source: WordNet 3.1, Princeton University