Verb has 2 senses

• zero in(v = verb.competition) home in, range in - direct onto a point or target, especially by automatic navigational aids;

Sample sentence:
Somebody ----s PP

• zero in(v = verb.change) zero - adjust (as by firing under test conditions) the zero of (a gun); "He zeroed in his rifle at 200 yards"

Sample sentence:
Somebody ----s something