| OAS | old age security; oral allergy syndrome; osmotically active substance |
|---|---|
| OASDHI | Old Age, Survivors, Disability and Health Insurance |
| OASDI | Old Age Survivors and Disability Insurance |
| OASI | Old Age and Survivors Insurance |
| TAM | tamoxifen; teen-age mother; thermoacidurans agar modified; time-averaged mean; total active motion; ... |