"I knew it all ___" (5)
I believe the answer is:
along
(Other definitions for along that I've seen before include "Lengthwise" , "From one end to the other" , "Sea monster, opposite Charybdis" , "together" , "Lining" .)
I believe the answer is:
along
(Other definitions for along that I've seen before include "Lengthwise" , "From one end to the other" , "Sea monster, opposite Charybdis" , "together" , "Lining" .)