Hello Mehrdad, This is a colloquial word. The prefix "под" means also "incomplete action" (it's colloquial meaning). So подизучил
Dear Mehrdad, The verb подрезать is a colloquialism and mostly ignored by lexicographers who have enough work with standard literal language.
Dear Mehrdad, Both statements are a little odd but it's possible that I am not familiar this specific field. In any case, below are the direct, most probable translations. Without a context, cannot