The lowest digit? (3)
I believe the answer is:
toe
'the lowest digit?' is the definition.
(digit low on the body)
'the lowest digit?' is the wordplay.
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'lowest digit?' becomes 'oe' (I can't justify this - if you can you should give a lot more credence to this answer).
't'+'oe'='TOE'
Can you help me to learn more?
(Other definitions for toe that I've seen before include "One with sock on" , "one digit?" , "Pedal extremity" , "End of foot" , "One's nailed" .)