| FOC | fronto-occipital circumference |
|---|---|
| OA | obstructive apnea; occipital artery; occipito-anterior; occiput anterior; octanoic acid; ocular albi... |
| occ | occasional; occiput, occipital; occlusion; occlusive; occupation; occurrence |
| occip | occiput, occipital |
| OCS | occipital condyle syndrome; Ondine's curse syndrome; open canalicular system; oral contraceptive ste... |