It (a people, or party,) collected together; (A, Mgh, TA;) [and] so ↓جَمَرَ; this verb being intrans. as well as transitive: (Msb: [see 2:]) and ↓جمّرit (a tribe) collected together, and became one band. (As, TA.)
2.
It (an army) became detained in the territory of the enemy, and was not brought back (S, K) from the frontier; (S;) as also ↓استجمر. (K.)