Make two from one bit - about half a second! (6)
I believe the answer is:
bisect
'make two from one bit about half a second' is the definition.
I can't judge whether this defines the answer.
'bit about half a second' is the wordplay.
'about' is an insertion indicator.
'half a' indicates taking half.
'second' with half the letters taken is 'sec'.
'bit' going around 'sec' is 'BISECT'.
Can you help me to learn more?
(Other definitions for bisect that I've seen before include "cross" , "Cut twenty [IN TWO]" , "create schism?" , "Cut in two equal parts" , "Cut or divide in two" .)