also: apex alignment · apexed · apex defender
Splitting the difference. A defender apexed between two people is standing halfway between them so he can get to either.
2 meanings, all below. Jump to the one you heard.
An alignment halfway between two reference points, most often between the end man on the offensive line and a slot receiver. It is a compromise by design: near enough to the box to fit a run, near enough to the slot to carry him, committed to neither. Coaches use it as a verb as well, apexing a linebacker between two threats.
apex alignment, apexedoverhang, cover downUsed as a noun for the player standing there, in the same way a technique number becomes a player. The apex and the overhang are often the same human being described by two different things about him: where he is, and what he is between.
apex defender, the apexoverhang