Susuma (often written Suṣama) is a term used in Jain cosmology to describe one of the six aras (epochs) within the descending half-cycle, Avasarpini.

• What it means

- Susuma means happiness or a period of (extreme) happiness. In the standard sequence of Avasarpini, the six aras are: 1) Suṣama-suṣamā (extremely happy) 2) Suṣama (happy) 3) Suṣama-duṣamā (happiness with some sorrow) 4) Duṣama-suṣamā (sorrow with some happiness) 5) Duṣamā (sorrow) 6) Duṣamā-duṣamā (extreme sorrow) - So “susuma” is the part of the cycle where happiness prevails, and it appears as either the first or second phase in the six-aras sequence, depending on which specific era name is being cited. Some texts list it as Suṣama-suṣamā (the peak of happiness) and others refer to the next stage simply as Suṣama (happiness). In short, susuma denotes the era of happiness in the avasarpini timeline. ( jainworld.jainworld.com)

• Digambar vs. Śvetambar notes

- Both traditions use the same framework of two halves (utsarpini and avasarpini) and six aras within each half. The exact phrasing or division names may vary slightly in some texts, but the essential meaning—susuma as a period of happiness within Avasarpini—is shared. ( jainknowledge.com)

If you’d like, I can point to a concise Jain source that explains the arā sequence and where susuma fits in.