(a) iyi tesir bırakmaya çalışmak, iyi tarafını göstermek, (b) hızlı yürümek, acele etmek.
It's a long way to the village, but if you put your best foot forward you'll reach it before the evening. (c) çok gayret sarfetmek, elinden geleni yapmak.
You've been so lazy in the past few months, you'll have to put your best foot forward if you want to pass that examination now.