ob-

ob- [äb, əb]

[< L ob, toward, for, about, before < IE base * epi-, * opi-, near, at, toward, after > Gr epi] prefix

1. to, toward, before, in front of [obtrude]

2. opposed to, against [obstinate]

3. upon, over [obscure]

4. completely, totally [obdurate]

5. inversely, oppositely [obovoid]: In words of Latin origin it becomes oc- before c;of- before f;o- before m; and op- before p