(also oc- before c ; of- before f ; op- before p )
■ prefix forming words of mainly Latin origin, meaning:
1》 to, towards: obverse.
2》 against; blocking: opponent.
↘concealment: occult.
3》 finality or completeness: obsolete.
4》 technical in a direction or manner contrary to the usual: obconical.
Origin
from L. ob 'towards, against, in the way of'.