In Jain geography / cosmology, “avakashantar” (ava­kāśāntar) means:

The empty interval of space between two things.

Breakdown:

• Avakāś = space (ākāś dravya) – the substance that gives “room” to all other substances.
• Antar = gap / interval / in‑between.

So avakashantar is the space-gap:

• between two bodies,
• between two regions (like different parts of loka),
• or simply the empty stretch of space not filled by matter (pudgal), but still part of the space substance (ākāś).

In Jain geography of the universe (loka):

• All lok (upper, middle, lower) exists within lokākāś (universe-space).
• Within this, wherever there is no body (no jīva‑body, no pudgal‑aggregate, no island/ocean etc.), that empty room is called an avakashantar – a pure space‑interval which allows movement of beings and matter.

Digambar and Shvetambar:

• Both accept the same basic idea: ākāś as space, and avakash / avakashantar as its portions or gaps.
• There may be small differences in technical wording in commentaries, but the meaning “space‑interval / empty gap of space” is the same in both traditions.