Frontier [patched] — Fling Trainer Farthest

Given it’s a cryptic clue style, I think you’re solving for (piece of footwear).

It sounds like you’re describing a puzzle or cryptic clue where the words and “frontier” are each connected to a single “piece.” fling trainer farthest frontier

One strong answer that fits all four is: Given it’s a cryptic clue style, I think