Small number did you say? That was close! (4)
I believe the answer is:
phew
I'm afraid I can't even guess how this answer relates to the clue.
Can you help me to learn more?
(Other definitions for phew that I've seen before include "Gosh, I'm sweltering!" , "Exclamation of relief" , "I'm overheating?" , "Sound relieved" , "Recover unharmed" .)