in effect

1.  For all practical purposes, as in This testimony in effect contradicted her earlier statement. [Late 1500s]
2.  In or into operation, as in This law will be in effect in January. Related phrases include go into effect and take effect, which mean "become operative," as in This law goes into effect January 1, or It takes effect January 1. Similarly, put into effect means "make operative," as in When will the judge's ruling be put into effect? [Late 1700s] Also see in force, def. 2.

The adjective has one meaning:

Meaning #1: exerting force or influence
  Synonyms: effective, good, in force

The adverb in effect has one meaning:

Meaning #1: in actuality or reality or fact
  Synonym: effectively