si-(modal) +∅-(3rd person subject prefix) + -∅-(classifier) + -nil (neuter perfective stem of root-NIL, “to handle several objects”).
sinil
This verb is semantically limited to expression in the third person and refers to a single group. For multiple groups, use the verbnaaznil.
This is a neuter verb. As such, it has only the perfective stem.
Paradigm: Neuter perfective (si), third person only.